Yes, It's A Headache. No, You Don't Need A Brain Scan

By Nancy Shute

Published March 18, 2014 at 10:28 AM EDT

Younger women are most likely to go to the doctor with a headache.

Headaches may be the most common human malady, accounting for one-quarter of all doctor visits.

It's almost always just a headache. But what if it's a brain tumor? Shouldn't I get a CT scan or MRI exam just to make sure?

Evidently I'm not alone in that thought. People in the United States get $1 billion worth of brain scans each year because they have a headache, according to researchers at the University of Michigan.

But since headaches are almost never caused by a tumor or other serious brain problem, that $1 billion is money down the drain, according to Dr. Brian Callaghan, the assistant professor of neurology who led the study.

"It's such a big number," Callaghan told Shots. "It's just an incredible number of MRIs and CTs that people get."

From 2007 to 2010, people visited the doctor 51 million times for headache-related problems, according to a national database of outpatient visits. And 12 percent of the time, the doctors sent their patients for a brain scan. Those numbers are on the rise, the analysis found, even though guidelines urge doctors to shun the scans. The results were published Monday in JAMA Internal Medicine.

Our scan-happy habits not only waste money, Callaghan says, but expose us to harm that can come from putting a healthy head in a scanner. There's needless radiation exposure from a CT, for one. And MRIs often turn up false positives — things that though they look odd will never cause any harm, yet can prompt a cascade of tests and invasive procedures.

"Most headaches are not caused by something bad," Callaghan notes. "Even people with brain tumors rarely have headaches." Instead, the overwhelming majority of headaches are tension headaches or migraines.

Both doctors and patients are to blame for the brain scan craze, Callaghan says.

Doctors order scans because it gets patients out the door quickly and makes them feel like the doctor is taking care of them. And patients ask for scans because, well, they're worried.

So doctors need to quit being so quick to grab the referral slip, Callaghan says, and patients need to presume they're not going to get a scan. "I actually find that most patients are quite reasonable if you're willing to explain all the things that went into deciding why not to get a scan."

When should someone worry? If a severe headache strikes suddenly, the neurologists say. People also should seek medical help for headaches that are markedly different than ones in the past, are brought on by exertion, or come with fever, vomiting, loss of coordination, or a change in vision, speech or alertness.