Many people first notice Behçet’s disease when mouth sores keep coming back—often painful, shallow ulcers that look like canker sores but recur in clusters and heal, then return. Some then develop genital sores, eye redness with pain or blurry vision, or tender red bumps on the legs, and may link these flare-and-calm patterns only after several episodes. Doctors are often alerted by this combination of recurring ulcers and inflammation, so keeping notes or photos of flares can help show the first signs of Behçet’s disease and how Behçet’s is first noticed.