Several years ago, a friend’s doctor called to tell him that the results of his PSA test (which measures prostate specific antigen to identify possible prostate cancer) showed levels that were three times higher than normal. As images of his life insurance beneficiaries started to flash before his eyes, his doctor quickly suggested that he get retested because the result might have been a “false-positive” (that is, a mistaken finding of disease that is not present). He was retested at another lab, and the results were normal.

False-positive test results are more common than you might think. Over the course of a lifetime, one in four women will get at least one false alarm from a mammogram. Each year, about 3 million women will get Pap smear results suggesting an abnormality in their cells. Yet only one in 1,000 turns out to be malignant. Blood test results, including those for cholesterol, also can be inaccurate.

What often gets overlooked, however, is the fear and panic that patients suffer due to false-positive test results. According to a recent study, a woman’s anxiety and fear can equal that of someone who truly does have breast cancer. And those effects can last for up to three years. So what can you do to protect yourself or a loved one? My advice…

Aim for Monday or Tuesday. When your doctor orders a test, try to schedule it early in the week. Results from the majority of widely used medical tests can be sent to your doctor within a day. Ask that he/she let you know the results promptly when they are received. If the results suggest a problem, your doctor can order a follow-up or retest by midweek. This eliminates the anxiety of waiting over the weekend or longer if you need to repeat the test or have other follow-up tests. Helpful: Many hospitals and testing facilities now provide prompt test results (for mammograms, CT scans and MRIs, for example) and follow-up testing if necessary. To save yourself both time and anxiety, check in your area for testing centers, hospitals and labs that offer such services.

Follow the rules. Many false-positive results occur because patients don’t follow pretest instructions. Cholesterol test results may come back too high (in the danger zone) because the patient failed to fast 12 hours prior to the test. Other tests report inaccurate results because patients didn’t stop taking certain medications or supplements before the test. Ask your doctor to carefully go over what you should or shouldn’t do in the hours or day(s) before the test.

Try not to worry. Sure, it is easier said than done, but remember, false-positive test results are common. When a test result suggests that something is wrong, do your best not to panic. By following the advice above, you can quickly determine if there really is a problem. And most importantly, don’t let false-positive test results stop you from getting the medical tests you need. My friend continued to have his PSA checked and will do so until a better test comes along!