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Headache is a very common disease in the U.S.A. Every year, about fifty million people have to go to the doctor because of headache. The symptoms of a headache are various. People can see black dots or bright spots in front of their eyes. They may also have pains only on one side of the head. Sometimes when the pain goes away, the head is sore. People have headache when they work too hard or they are too nervous about something. Medicine can help cure the disease but people usually have to do more than taking tablets. They can prevent headaches by changing their diets or their lifestyle or simply by going to bed.