According to the National Headache Foundation, how many people in the United States suffer chronic headaches?

Have you had a headache recently? If your answer is yes, you are like many millions of people worldwide who experience pain in the head. The pain can be temporary, mild and cured by a simple painkiller like aspirin. Or, it can be severe.  The National Headache Foundation says more than forty five million people in the United States suffer chronic headaches.  Such headaches cause severe pain that goes away but returns later. Some headaches may prove difficult and require time to treat. But many experts today are working toward cures or major help for chronic headaches.