It is bad enough to have an illness. But there are times when the cure is as bad as the illness itself, and worse, it is possible that the cure itself can become the cause of the illness.

Many people suffer headaches daily due to a number of different reasons, the causes of which are as diverse as undiagnosed jaw disorders, genetic susceptibility and stress. However, recent research shows that a growing number of headaches are being caused by the very medications taken to alleviate them. Almost half of chronic migraine headaches, and as many as 25 percent of all headaches, are actually ?rebound? episodes triggered by the overuse of common pain medications, such as prescription and over-the-counter drugs.

Oftentimes, people tend to pop too many pills in dealing with a migraine or a simple tension-type headache. But when the medications stop, another headache follows, which may be similar to a hangover. This will prompt them to seek the medicine cabinet again, and before long they become hooked in a cycle of headaches and over-medication.

There are more than three million Americans suffering from headaches they are inflicting on themselves, according to Dr. Stephen D. Silberstein, a professor of Neurology and director of the Jefferson Headache Center at Thomas Jefferson University in Philadelphia. ?If a patient's headaches have grown markedly worse or more frequent, the problem is almost always medication overuse,? Dr. Silberstein said.

The International Headache Society last year published revised criteria to help doctors recognize and treat headaches from medication overuse. Signs of trouble include headaches that occur 15 or more days a month, according to the society, along with the heavy use of pain medications for three months or more. Overuse is defined as taking pain medication for 15 or more days a month.

?Overuse has less to do with how many pills you take to relieve a single headache than with how often you take them,? said Dr. Robert Kunkel, a headache specialist at the Cleveland Clinic Headache Center. ?If you get more than two headaches a week and take pain pills for them, you're at risk.?

The use of a certain medication may be discontinued in order to know whether it is the cause of a certain headache. For medication-dependent patients, this test may take as long as two months before an improvement can actually be seen.

People who experience migraine seem to be especially susceptible to rebound episodes. Many doctors begin weaning these patients off painkillers by prescribing drugs to help prevent attacks, then gradually reducing doses of the painkillers used to treat acute episodes.

One of several drugs that have been approved to prevent migraines is topiramate (Topamax), which studies suggest may lessen the frequency of attacks for up to 14 months. Moreover, early trials reveal that Botox injected into the scalp can prevent or reduce the frequency of both migraines and tension headaches.

Although the Food and Drug Administration has yet to approve the use of botulinum toxin for headaches, it is already being offered by a growing number of clinics due to its ability to provide relief for up to three months.

It is encouraging to know that tension headaches can actually be prevented with stress reduction techniques and avoidance of certain triggers. With close attention to prevention, those who suffer from tension headaches may not need to resort to painkillers often enough to risk rebounding. Almost any kind of pain reliever can cause rebound problems if use in excess. However, most patients show dramatic improvement after three months of being weaned from medication. They also learned their lesson and steer clear of overusing pain pills.