A headache is defined as pain or aching that occurs in the head, face, mouth, or neck. It is one of the most common symptoms experienced in society today, affecting approximately 90 percent of men and 95 percent of women. A headache occurs when the ends of pain-sensitive nerves are stimulated by things such as stress, muscular tension, or dilated blood vessels. There are several types of headaches, including migraine headaches, tension-type headaches, and cluster headaches. Treatment options for headaches can include medications, lifestyle changes, and alternative treatments.