A physician sits at a desk.

Having a screening test—which looks for signs of a disease before it shows symptoms—sounds like a good idea. And it can be. For instance, in the U.S., regular screening is thought to have contributed to a 50 percent reduction in deaths from cervical cancer over the last 30 years, according to the American Cancer Society.

Yet not every screening test is right for every person, and it’s important, in partnership with your doctor, to determine whether a test you’re considering is really right for you.

Asking your doctors certain questions can help you figure this out. Try these:

1. How will this benefit me? Your doctor should be able to explain how scientific evidence backs up the use of a screening for you. And remember: “It only makes sense to get screened if you're testing for something you can do something about—and if treatment is more effective when the problem is detected before symptoms develop,” says Steven Woloshin, M.D., co-director of the Center for Medicine and Media at Dartmouth University’s Dartmouth Institute.

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2. What are the potential downsides? Most screenings can cause anxiety about possible results, as well as false positives. The latter can lead to additional testing that may carry risks such as infection, or even treatments you don’t really need. Your doctor should be able to explain how likely you are to experience a screening harm such as a false positive, based upon your personal health history. For example, women who have dense breasts or who are taking estrogen may be more likely to have a false positive result from a mammogram.

3. What’s the best screening option for me? Your doctor should be able to explain the different strategies available to you, and their risks and benefits for you. For example, some medical groups recommend having a mammogram every year, while others advise it every two years. And screening for colon cancer could mean a colonoscopy once a decade—or a stool test once a year.

4. What might happen if I don’t have this screening? Your doctor should be able to explain your chances of being significantly harmed or dying from the disease in question—both if you get screened, and if you choose not to. And your personal preferences may play a role, says Kimberly Wintemute, M.D., primary care co-lead for Choosing Wisely Canada—in some cases, you may decide that getting a certain screening test isn’t worth the potential downsides. “The option of doing nothing is sometimes the best option,” she says.