Headaches are such a common condition that they are almost considered a normal part of living. They affect approximately 95 percent of women and 90 percent of men. A headache occurs when certain nerves are stimulated by specific triggers, such as stress, muscle tension, or dilated blood vessels.
There are so many varieties of headaches that healthcare providers will separate them into different groups, such as primary and secondary; acute, subacute, and chronic; or vascular, muscle contraction (tension), traction, and inflammatory. Although many headaches don't require medical attention, there are certain symptoms that you should watch out for and report to your healthcare provider if you experience them (such as a sudden, severe headache or headaches that accompany a fever or convulsions).