7 Medical Tests and Treatments You May Not Really Need

6.  Diagnostic tests for suspected allergies.

American Academy of Allergy, Asthma & Immunology

Some 35 million Americans suffer from seasonal allergies. And millions of Americans increasingly blame a food allergy or sensitivity — from gluten to milk — for their health woes. Some doctors or health providers now perform a blood test, called an immunoglobulin (IgG), for food allergies. But Linda Cox, M.D., president elect of the allergy group, says the test simply doesn't work. For seasonal allergies, many doctors run a battery of blood and skin tests dubbed IgE, when just a few specific tests would do. By asking patients when and where they have symptoms, doctors can pinpoint what tests they should run.

Dangers: The superfluous use of allergy medications; an overly restricted diet.

7.  CT scans and other imaging procedures for uncomplicated headaches.

American College of Radiology

Severe headaches can be excruciating and frightening, but unless they are accompanied by other key symptoms it rarely makes sense to get a CT scan or MRI of the brain. Yet "it happens all the time," says David Seidenwurm, M.D., a neuroradiologist in Sacramento, Calif. Patients get frightened, doctors worry about lawsuits and people "want all the information right away," he says. "It's easier to do the scan than to have the conversation."

Dangers: Radiation exposure raises cancer risks in the population and false-positives lead to more testing and patient anxiety.

Exceptions: Worrisome symptoms — trouble speaking, blurred vision, weakness on one side — or other signs that the headache is caused from something more dangerous, such as a brain tumor.