Hypnic headache is a rare headache disorder that wakes people from sleep, often at the same time on repeated nights. It usually causes a dull or throbbing head pain, and some people also feel nausea or become sensitive to light or sound. Many living with hypnic headache are older adults, though it can happen at other ages, and episodes may continue for months or years. Not everyone will have the same experience, but the early symptoms of hypnic headache often begin only during sleep and are not usually a sign of a life-threatening illness. Treatment for hypnic headache often helps and may include caffeine before bed, lithium, or certain other headache medicines chosen by a doctor.
How many people live with Hypnic headache?
Hypnic headache is very rare, but a reliable worldwide estimate of how many people live with it has not been established; the published information is mostly from small reports of people seen in headache clinics, not large population studies. The same is true in the United States, where no recent, authoritative national estimate is available for how many people are living with hypnic headache.
Overview
Hypnic headacheSymptoms
Hypnic headache causes headaches that wake people from sleep, often at the same time on repeated nights. The pain is usually dull or throbbing, often on both sides of the head, and may come with nausea or sensitivity to light or sound.
Outlook and prognosis
Hypnic headache is usually long-term but not dangerous, and many people improve with bedtime treatment. The outlook is generally good, although attacks can disrupt sleep and daytime energy, and some may have flare-ups for years.
Causes and risk factors
The exact cause of hypnic headache is unknown, but it likely involves brain areas that regulate sleep and pain. Risk rises with older age, and many living with hypnic headache are women.
Genetic influences
Genetics do not seem to play a major role in hypnic headache. Most cases are sporadic, and no specific gene changes are known to clearly cause it. Rare family patterns have been reported, so genetics may matter in some people.
Diagnosis
Hypnic headache is diagnosed mainly from your symptom pattern, especially headaches that wake you from sleep on multiple nights each month. Doctors also rule out other causes, often with a neurological exam and sometimes brain imaging or sleep studies.
Treatment and drugs
Hypnic headache is often managed with treatment taken at night. Many living with hypnic headache improve with bedtime caffeine, such as coffee or a caffeine tablet. If attacks continue, a doctor may suggest lithium, indomethacin, or melatonin.
Symptoms
Hypnic headache often shows up as a headache that wakes you from sleep, sometimes so regularly that the pattern becomes hard to ignore. Many living with hypnic headache feel fairly normal during the day between attacks, but the broken sleep can still take a toll. You might notice small changes at first: the early symptoms of hypnic headache can seem like occasional nighttime headaches before the timing starts to look more consistent.
The pain begins during sleep and wakes you up rather than starting while you are already awake. It often happens after a few hours of sleep, which can make the pattern feel especially noticeable.
Attacks often come at a similar time on different nights or happen on many nights in a month. That repeated timing is one of the most recognizable symptoms of hypnic headache.
The pain is often described as a dull ache, pressure, or a throbbing feeling. It is usually mild to moderate, but it can be strong enough to make it hard to fall back asleep.
Many people with hypnic headache feel pain on both sides of the head or across the whole head. Some have one-sided pain instead, so the location can vary.
How people usually first notice Hypnic headache?
Many people first notice hypnic headache when a dull or throbbing headache starts during sleep and actually wakes them up, often at nearly the same time several nights a week. The first signs of hypnic headache are usually this repeated pattern of nighttime attacks rather than daytime pain, and some people also notice nausea, sensitivity to light or sound, or a headache that lasts from about 15 minutes to a few hours after they wake. Because headaches that begin only during sleep can have other causes too, this kind of clockwork pattern is often the clue that prompts people to seek medical care.
Types of Hypnic headache
Hypnic headache does not have widely accepted formal subtypes, but many living with hypnic headache notice a few recurring patterns in how attacks feel and how often they happen. Symptoms don’t always look the same for everyone. For many, this can mean pain on both sides of the head, while others have one-sided pain or added nausea, light sensitivity, or sound sensitivity. Early symptoms of hypnic headache are often simply waking from sleep with a dull or throbbing headache at a similar time of night.
Bilateral pain
This is the most common pattern, with pain felt on both sides of the head after waking from sleep. The pain is often dull or pressure-like, though some people describe it as throbbing.
One-sided pain
Some people with hypnic headache feel pain mainly on one side of the head. This can make it seem more like other headache disorders, especially if the pain is stronger or more localized.
Mild to severe
Hypnic headache can range from fairly mild to quite painful, and the intensity may not be the same from night to night. Even within the same type, intensity can range from mild to severe.
Migraine-like features
A smaller group also has nausea or sensitivity to light or sound during attacks. When these features are present, hypnic headache can overlap in feel with migraine, even though it starts during sleep.
Attack length
Episodes can be brief for some people and last much longer for others, often from about 15 minutes to several hours. The balance of symptoms can shift over time.
Frequency pattern
Some people have attacks only a few nights each month, while others wake with hypnic headache much more often. These differences affect sleep and daytime energy, but they are not considered separate types of hypnic headache.
Can I slow down the onset of symptoms?
Probably not in any proven way: there is no strong evidence that lifestyle changes or medicines can meaningfully delay when hypnic headache, a rare headache that wakes people from sleep, first begins. Research is limited, and while a steady sleep schedule, treating sleep problems, and avoiding personal triggers such as alcohol may help some people have fewer attacks, these steps have not been shown to prevent the condition or push back its onset. The most helpful step is usually early medical review to confirm the diagnosis and talk about ways to reduce attacks, which can still make a real difference even if it does not change when the condition starts.
What genetics can tell you about symptoms
For hypnic headache, genetics does not currently give doctors a clear way to predict which symptoms someone will have, how severe attacks will be, or exactly when they will start. Unlike some inherited conditions, hypnic headache has not been tied to one well-established gene pattern, and most cases seem sporadic rather than strongly family-linked. That said, genes may still play a small part in how the brain handles pain and sleep, but this is still being studied and is not yet useful for routine symptom prediction.
Causes and risk factors
Hypnic headache can wake people from sleep at the same time night after night, and its exact cause is still not clear. Doctors think it may relate to changes in the brain systems that control pain, sleep, and the body clock, and it is seen most often in adults over 50. A strong inherited cause for hypnic headache has not been found, so family history is not a major risk factor for most people. Anything that disrupts normal sleep, such as shift work, jet lag, or irregular sleep habits, may play a part in some people, but these are not proven causes. Researchers are still learning how these pieces fit together.
What are the most common causes or risk factors?
The exact cause of hypnic headache is not known, but it seems to be linked to changes in the parts of the brain that help control sleep, pain, and the body clock, which may explain why the headache starts during sleep. It is most often seen in older adults, especially after age 50, and it appears to be somewhat more common in women. Many people with hypnic headache also have a history of migraine or another headache disorder, but a strong inherited or family-linked cause has not been clearly shown.
Environmental and biological risk factors
Hypnic headache is a rare headache disorder that wakes people from sleep, usually later in life. The clearest risk factors for hypnic headache are biological rather than environmental. Researchers are still exploring how outside influences interact with our inner biology. Right now, only a few patterns are well established.
Hypnic headache most often begins after age 50. It is uncommon in younger adults, which suggests that age-related changes in sleep and pain-control systems may raise risk.
Studies suggest hypnic headache is somewhat more common in women than in men. This does not mean men cannot develop it, but sex-related biological differences may play a part.
Hypnic headache occurs during sleep, not while people are fully awake and active. Attacks often happen at a similar time at night, which points to sleep timing as an important biological factor.
The brain systems that regulate sleep, wakefulness, and pain seem to be involved in hypnic headache. Changes in this internal timing system become more common with aging and may help explain who gets hypnic headache.
Genetic risk factors
Most people with hypnic headache do not have a clear inherited cause. Right now, the genetic causes of hypnic headache are not well defined, and no single gene has been proven to cause it. Small family clusters have been reported, which suggests genes may play a part for some families. Risk is not destiny—it varies widely between individuals.
No single gene: Researchers have not identified one gene that reliably explains hypnic headache. This is why genetic testing is not a routine way to assess risk for most people with this condition.
Family history: A few families have had more than one relative with hypnic headache or similar night-time headache patterns. This suggests an inherited tendency may exist in some cases, but it appears to be uncommon.
Migraine overlap: Some people with hypnic headache also have a personal or family history of migraine. This may reflect shared inherited factors in how the brain processes pain, but it does not explain most cases.
Lifestyle risk factors
Lifestyle risk factors for hypnic headache are not as well defined as they are for migraine or tension-type headache, but daily habits can still influence how often attacks occur or how disruptive they become. Because hypnic headache is closely linked to sleep, routines that disturb nighttime sleep or alter normal sleep timing may matter most. Certain food and drink habits, especially alcohol use and caffeine patterns, may also affect some people. Regular routines and attention to individual triggers are often the most practical ways to reduce episodes.
Frequent changes in bedtime, wake time, or sleep duration may disrupt the sleep patterns linked to hypnic headache. Shift work, repeated late nights, or sleeping much longer than usual can make nighttime headaches more likely in some people.
Fragmented sleep, long periods awake in bed, or inconsistent bedtime routines can worsen overnight sleep quality and may increase attacks. Good sleep hygiene cannot cure hypnic headache, but it may reduce avoidable sleep disruption that sets the stage for pain.
Alcohol in the evening can disturb sleep architecture and may trigger nighttime headaches in susceptible people. Reducing or avoiding alcohol close to bedtime may help if attacks cluster after drinking.
Too little, too much, or poorly timed caffeine can affect sleep and may change headache patterns. Some people with hypnic headache notice that caffeine late in the day worsens sleep, while others are advised by clinicians to use caffeine strategically, so personal response matters.
Risk prevention
Many living with hypnic headache are most concerned about waking in the night again and again, sometimes at nearly the same hour. There is no proven way to fully prevent hypnic headache from starting, but some steps may lower the chance of attacks or reduce how often they happen. Prevention is about lowering risk, not eliminating it completely. If you are wondering how to prevent hypnic headache, the usual approach is to look for patterns, avoid common triggers, and discuss preventive treatment with a doctor.
Going to bed and waking up at regular times may help keep nighttime headaches from being triggered by sudden changes in sleep. Big shifts in schedule, frequent sleep loss, or sleeping in much later than usual can make attacks more likely for some people.
A headache diary can help you notice whether alcohol, stress, certain medicines, or changes in sleep seem to come before an attack. Writing down the time of night, what you ate or drank, and how often headaches happen can make treatment decisions clearer.
For some people with hypnic headache, a small amount of caffeine before bed may help prevent attacks during the night. This is not right for everyone, especially if caffeine worsens insomnia, palpitations, or anxiety, so it is best discussed with a clinician.
Some people with frequent hypnic headache need medicines that are used to prevent attacks rather than treat them after they start. A doctor may suggest options such as caffeine, lithium, or indomethacin, depending on your age, other health conditions, and side effect risks.
Can you prevent Hypnic headache?
There is no sure or proven way to prevent hypnic headache, and there are no clearly established lifestyle risk factors you can control. Some people living with hypnic headache have fewer nighttime attacks with a doctor’s preventive treatment, sometimes including caffeine before bed, but it does not work for everyone.
Transmission
If you wake from sleep with head pain, it is natural to wonder whether hypnic headache can spread or run in families. Hypnic headache is not infectious, which means it cannot be passed from person to person through touch, coughing, kissing, sex, food, or water.
Hypnic headache is a primary headache disorder, so it starts within the body rather than from a virus or other germ. There is also no clear, usual inherited pattern, so the genetic transmission of hypnic headache is not established. For many living with hypnic headache, this means there is no need to isolate or worry about giving it to a partner, child, or anyone else in the home.
When to test your genes
For hypnic headache, genetic testing is not routinely recommended because no established gene test helps detect it early or tailor treatment. If your headaches are unusual, started young, or come with a strong family history of inherited neurologic disease, your clinician may consider a broader evaluation for another cause.
Diagnosis
Hypnic headache is usually diagnosed by the pattern of symptoms, especially headaches that wake someone from sleep at about the same time on repeated nights. Because other conditions can also cause nighttime headaches, doctors focus on ruling out more serious causes before confirming how hypnic headache is diagnosed. It’s natural to worry when symptoms don’t have a clear explanation.
Doctors ask when the headaches happen, how often they wake you up, how long they last, and whether one or both sides of the head are affected. A diary of attacks, sleep timing, and pain features can make the diagnosis of hypnic headache much clearer.
A physical and nerve system exam helps look for signs that suggest a different cause of headache. In people with hypnic headache, this exam is often normal between attacks.
MRI, and sometimes CT, may be used to check for problems such as a brain tumor, bleeding, or pressure changes that could cause headaches during sleep. Imaging is especially important if the headaches are new, changing, or paired with other warning signs.
Doctors may ask about snoring, pauses in breathing, poor sleep, or unusual movements at night. This helps separate hypnic headache from sleep apnea and other sleep disorders that can trigger morning or nighttime head pain.
How is Hypnic headache diagnosed?
Hypnic headache is usually diagnosed from the story of the headaches, because there is no single test for it. A doctor looks for a very specific pattern: the headache starts during sleep and wakes someone up, happens on many nights over time, and lasts from about 15 minutes to 4 hours, while the rest of the symptoms do not point more strongly to another headache type. They also do an exam and often order tests such as a brain scan, and sometimes sleep testing or blood tests, to rule out other causes of nighttime headaches.
Stages of Hypnic headache
Hypnic headache does not have defined progression stages. That is because it is usually described by a pattern of repeated headaches that wake people from sleep, rather than a condition that steadily moves from one stage to the next. Doctors usually start with a conversation about when the headaches happen, how long they last, and whether there are any warning signs that suggest another cause. Because the early symptoms of hypnic headache can overlap with other headache disorders or sleep-related problems, diagnosis often also involves an exam and sometimes brain imaging or other tests to rule out more serious conditions.
Outlook and prognosis
The outlook for people with hypnic headache is generally good, because it is considered a benign primary headache disorder and is not known to cause stroke, brain damage, or progressive neurologic decline. Many people have recurrent attacks over months to years, often with periods of improvement or remission, while others continue to have chronic but manageable symptoms. With appropriate treatment, such as bedtime caffeine, lithium, indomethacin, or other preventive options, attack frequency and severity can often be reduced substantially. Mortality is not increased by hypnic headache itself, but ongoing nighttime headaches can impair sleep, daytime functioning, and quality of life if not controlled. Prognosis also depends on careful evaluation to exclude secondary causes of nocturnal headache, especially when symptoms are new, atypical, or changing.
Long-term effects
For many, hypnic headache means headaches that wake you from sleep over months or even years, rather than causing damage to the brain. The main long-term burden is usually broken sleep and the daytime effects that come with it. It’s important to remember that long-term does not always mean progressive, and many living with hypnic headache have a stable pattern over time.
Repeated nighttime attacks can break up sleep and make it hard to get enough deep, restful rest. Over time, this can leave many people with hypnic headache feeling unrefreshed in the morning.
Poor sleep can lead to tiredness, low energy, and trouble getting through work, school, or daily tasks. Some may find they are less focused or need more time to recover during the day.
Hypnic headache often follows a chronic pattern, with attacks returning regularly for months or years. The timing and frequency can change, but many people continue to have periods of recurring nighttime headache.
Waking with pain night after night can make bedtime stressful and reduce overall well-being. Many people notice small adjustments, like planning around poor sleep or worrying about when the next attack will hit.
How is it to live with Hypnic headache?
Living with hypnic headache can feel especially disruptive because the pain often arrives out of sleep, night after night, turning what should be rest into something unpredictable. For many people with hypnic headache, this means broken sleep, daytime fatigue, trouble concentrating, and worry about going to bed, even though the headaches are usually not dangerous and often can be managed with treatment. The ripple effects can reach beyond you too, since a bed partner or family member may also lose sleep, and repeated nighttime awakenings can strain work, mood, and daily routines for everyone in the household.
Treatment and drugs
Hypnic headache is usually treated with medicines taken before bed to prevent the nighttime headaches, since the goal is to reduce how often attacks happen and how severe they are. A small amount of caffeine at bedtime, often as coffee or a caffeine tablet, helps many people, even though that sounds unusual for a headache that wakes you from sleep. Other options may include lithium, indomethacin, or sometimes melatonin, depending on your age, other health conditions, and how often the headaches occur. Not every treatment works the same way for every person, so doctors often adjust the plan over time and watch for side effects, especially with medicines that can affect the kidneys, stomach, thyroid, or heart. Alongside treatment, keeping a simple record of when hypnic headache happens can help you and your doctor spot patterns and choose the safest, most effective approach.
Can you cure Hypnic headache?
No, there is not a known cure for hypnic headache right now. The good news is that treatment can often help prevent attacks or make them happen less often, such as having caffeine before bed or using medicines your doctor may suggest. Many people living with hypnic headache can get good relief once the right plan is found.
Non-drug treatment
Waking from sleep with a dull, steady headache can be frustrating, especially when it starts to shape your bedtime routine around worry. For people with hypnic headache, non-drug care is usually supportive rather than a full replacement for medication, but it can still make nights more predictable and help uncover triggers. Not every approach works the same way, and treatment often starts with sleep habits, tracking patterns, and checking for other sleep-related problems that may be adding to the burden.
Going to bed and waking up at about the same time each day may help stabilize the sleep pattern around hypnic headache. For many, treatment begins not at the pharmacy, but with a regular routine that reduces sudden shifts in sleep timing.
Writing down when headaches happen, how long they last, and what you ate, drank, or did before bed can help spot patterns. This can also help your clinician judge whether the early symptoms of hypnic headache are following a typical pattern or if something else needs to be checked.
A dark, quiet room, a wind-down routine, and less screen time before bed may make sleep more settled. Simple routines—like dimming lights or keeping bedtime consistent—can have lasting benefits.
Some people are advised to try a small amount of caffeine before bedtime as part of their care plan. Although making changes can feel daunting, this should be discussed with a clinician because it can help some people but disturb sleep in others.
Your genes may have an impact on how drugs work for you
For people living with hypnic headache, the medicines used to prevent or calm attacks, such as caffeine and a few prescription options, do not work the same way for everyone. Part of that difference may come from small inherited changes that affect how fast the body breaks down a medicine or how strongly the brain responds to it, so one person may do well with a low dose while another gets little benefit or more side effects like stomach upset, shakiness, or trouble sleeping. Right now, genetic testing is not a routine part of care for hypnic headache, and treatment is still mainly guided by your symptoms, your other health conditions, and how you respond over time.
Pharmacological treatments
Treatment for hypnic headache is aimed at preventing the nighttime attacks that wake people from sleep. Commonly used options include caffeine before bed, lithium, indomethacin, and melatonin, although the best treatment for hypnic headache can differ from one person to another. Not everyone responds to the same medication in the same way. Because these medicines have different side effects and safety concerns, a doctor usually helps choose the option that best fits your age, other health conditions, and headache pattern.
A cup of coffee before bedtime or a caffeine tablet is often the first treatment doctors try for hypnic headache. It can prevent attacks in many people without causing major side effects, though some may find it makes sleep lighter or harder to maintain.
Lithium can be very effective for frequent or severe hypnic headache, especially when caffeine is not enough. It needs careful monitoring because it can affect the kidneys, thyroid, and fluid balance, and it may not be suitable for older adults or people with heart or kidney problems.
Indomethacin is a strong anti-inflammatory pain medicine that helps some people with hypnic headache. It can irritate the stomach and raise the risk of bleeding, kidney problems, or higher blood pressure, so doctors use it cautiously.
Melatonin may help reduce nighttime headache attacks and is sometimes chosen when a gentler option is preferred. It is usually well tolerated, but its benefit can be modest and it does not work for everyone.
Genetic influences
For most people with hypnic headache, doctors do not find a clear inherited cause. It’s natural to ask whether family history plays a role. So far, researchers have not linked hypnic headache to one specific gene or a clear pattern of inheritance, and most cases seem to happen sporadically rather than being passed directly from parent to child. Still, genes may have a small effect on systems involved in hypnic headache, including the brain’s sleep-wake timing and the way pain signals are handled, but the evidence is limited. If you are wondering whether hypnic headache is hereditary, the best summary is that genetics may contribute in some people, but this has not been firmly proven, and genetic testing is not usually part of diagnosis.
Is Hypnic headache genetic?
Genetics do not seem to play a major role in hypnic headache. Most cases are sporadic, and no specific gene changes are known to clearly cause it. Rare family patterns have been reported, so genetics may matter in some people.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are common and are a normal part of being human. Most do not directly affect health and simply reflect natural differences among people. For many genes, having a variant linked to a condition suggests a possible connection rather than a definite diagnosis, especially when several genes and factors in the environment are involved. In some cases, though, a single well-understood variant in a specific gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
If hypnic headache keeps waking you at the same time most nights, it can take time to find a treatment that helps without causing unwanted side effects. Not every difference in response is genetic, but small inherited differences in genes that help your body handle medicines can affect how some people respond to treatments sometimes used for hypnic headache, such as caffeine or melatonin. There is also broader evidence that gene differences can change the way some pain medicines work, but this has not been studied enough to reliably guide treatment for hypnic headache itself.
For now, treatment for hypnic headache is usually tailored more by age, sleep pattern, kidney health, other medicines, and whether options like caffeine, lithium, or indomethacin are safe for you. In practical terms, there is no routine genetic test used to choose the best medication for hypnic headache, although genetics may be one reason one person improves while another does not. If a medicine is not helping or is causing side effects, your doctor will usually adjust the dose or switch treatments based on your overall health rather than a specific gene result.
Interactions with other conditions
Many living with hypnic headache find that the headache itself is only part of the problem, because repeated night waking can leave them tired, foggy, or less able to cope with other health issues the next day. Hypnic headache can occur alongside other headache disorders, especially migraine, which can make the pattern harder to sort out when some attacks happen at night and others do not. Another important aspect is how it may link with other diseases: doctors often check for sleep problems such as obstructive sleep apnea, since hypnic headache and sleep apnea can both disturb sleep and may seem similar at first. In older adults, they also make sure the pain is not being caused by another medical condition that needs different treatment, such as very high blood pressure during the night or a new disorder affecting blood vessels. Some may also be dealing with insomnia, depression, or anxiety, which do not cause hypnic headache directly but can worsen sleep loss and make the condition feel more disruptive. Interactions can look very different from person to person, so if you are noticing early symptoms of hypnic headache or a change in your usual headache pattern, it is worth discussing how it fits with your other health conditions.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Hypnic headache?
Headaches that wake someone from sleep can also happen with migraine, cluster headache, sleep apnea, and headaches linked to using pain medicine too often or stopping caffeine. Doctors also make sure there is not another cause, such as very high blood pressure at night or, less often, another problem affecting the brain, because these can seem similar at first. The pattern of the pain, the time it happens, and whether there are other symptoms like tearing, stuffy nose, nausea, or loud snoring can help tell them apart.
History
Waking from sleep with a steady, often dull headache can feel especially strange because the rest of the day may be fairly normal. This pattern drew medical attention only relatively recently. In 1988, researchers described a small group of people whose headaches repeatedly began during sleep, helping define what is now called hypnic headache.
At first, doctors mainly recognized hypnic headache by its timing rather than by a lab test or scan. People living with hypnic headache were often older adults, and many had headaches that came at roughly the same time during the night, sometimes several nights a week. Because nighttime headache can also happen with other conditions, early reports focused on ruling out more serious causes before doctors became more confident that this was its own headache disorder.
As medical science evolved, descriptions became clearer and the picture broadened. Doctors learned that hypnic headache is uncommon, that it can affect both women and men, and that symptoms may vary from one person to another. Some have a mild to moderate ache, while others have more intense pain, and nausea or light sensitivity can occur in some cases. Over time, researchers also worked out how to separate it from other headache types that may wake someone from sleep.
In recent decades, awareness has grown, and that has made diagnosis easier for many. Earlier on, someone might have been told they had “just poor sleep,” migraine, or another headache type if the nighttime pattern was not recognized. Today, the history of hypnic headache helps explain why doctors pay close attention to details such as age at onset, how often the attacks happen, and whether the early symptoms of hypnic headache appear only during sleep or also at other times. Even though there is still more to learn, the condition is now well established in modern headache medicine.