Headaches are terrible; and when they are recurrent, as with migraines and chronic headaches, sufferers can become desperate for relief.

Because of their serious symptoms — severe pain, sensitivity to light and sound, and nausea — they may also raise red flags, suggesting more serious concerns, like brain tumors.

For this reason, neurologists or, more often, their patients request brain scans to rule out diagnoses requiring surgical intervention.

A new study calculates that the U.S. spends $1 billion per year on MRI and CT scans for migraine sufferers.

The problem is that the majority of these scans are unnecessary. Despite recommendations from various organizations to cut down on the number of brain scans ordered, doctors are actually ordering more scans for headache patients these days, in a very expensive effort to ease headache patients' concerns.

In a set of findings that provides insight into why healthcare costs are so high, a new study calculates that the U.S. spends $1 billion per year on MRI and CT scans for migraine sufferers. Between 2007 and 2010, Americans made 51 million headache-related visits to doctors, about half of which were for migraines. Over 12% of these visits resulted in a brain scan.

The researchers found that these scans cost almost $4 billion over these four years.

This remarkable cost might be justifiable if people complaining of headache were much more likely to be diagnosed with a serious problem (like brain tumor). But they’re not.

“There's solid research showing that the number of times you find serious issues on these scans in headache patients is about the same as that for a randomly chosen group of non-headache patients,” said lead author Brian Callaghan in a news release. “And a lot of the things we find on such scans aren't necessarily something we will do something about.”

Only about 1-3% of the scans done on people who go to their doctors for repeated headaches uncover something serious — tumors or blood vessel problems — about the same statistics as for the general population.

So the fact that in 2010, 14.7% of patients who went to their doctors for headaches ended up with a brain scan points to a problem, says Callahan. Doctors may be giving patients scans simply to put their minds at ease, even though the current guidelines don’t call for it.

Listen to your doctor’s advice: If he or she doesn’t think a brain scan is necessary, don’t push for one.

And there are more costs associated with unnecessary scans, like follow up tests and possible treatment if something, even harmless, is detected. Additionally, CT scans can pose radiation risks, and MRI scans have a high false positive rate — they find something where there is nothing.

Last year Callahan did a study that showed that the cost of all the brain scans within a given period was more than the cost of all neurologist visits in the same time. In most cases, insurance pays for the scans if doctors order them, even if it’s at the patient’s request, but these costs can add up and tax the country as a whole.

Callahan’s recommendation is to listen to your doctor’s advice: If he or she doesn’t think a brain scan is necessary, don’t push for one. If you feel in your gut that something more than headaches is going on, then keep an open line of communication with your doctor. But in many cases, the scans seem to be more trouble — and more cost — than they’re worth.

The study was carried out at the University of Michigan, and published in JAMA Internal Medicine.