pain or discomfort in the head or upper neck
A headache, also known as cephalalgia, is a pain or discomfort in the head or upper neck. It can be caused by a variety of factors, including stress, tension, dehydration, or underlying medical conditions such as migraines or sinus infections. Headaches can range from mild to severe and may be accompanied by other symptoms like nausea, sensitivity to light, or visual disturbances.