8 Health Test Secrets Doctors Don’t Tell You

By The Editors of Prevention

In the hectic flurry of your typical doctor's office, it's not surprising that doctors and nurses sometimes forget to share the helpful little directives that can make potentially lifesaving tests--like a Pap test or skin cancer screening--more accurate and comfortable. That's why we interviewed leading clinicians for the scoop on what to do and say to get the best care and results at your next health test.

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1. Chill out for 3 minutes before a blood pressure reading

Relaxing for 3 to 5 minutes before your blood pressure is taken ensures you won't have an artificially high reading, which can result in unnecessary prescription meds, says Texas cardiologist Sarah Samaan, MD, author of The Smart Woman's Guide to Heart Health. Running in to your appointment after a traffic-packed drive to the doctor, for example, can nudge your systolic pressure (the higher number) by as many as 20 points. Sit quietly, flip through a good book or magazine, and take deep breaths to calm down in the waiting room.

It's also a good idea to skip that Dunkin' Donuts run on the way to the doctor. Caffeine can cause a temporary blood pressure spike, says Dr. Samaan, although there's no good proof it causes hypertension in the long run. (Check out 13 more ways to lower your blood pressure naturally!)

2. Book a mammogram at the start of your menstrual cycle

If you're premenopausal, get your mammogram during the first 2 weeks of your cycle (the week of and after your period) to avoid hormonal shifts that can make your breasts more sensitive, says Barbara Jaeger, MD, director of mammography at American Radiology Services in Baltimore. Also, lay off caffeine for a week before the test--it increases tenderness, too. Skip deodorant (and powders, creams, and perfume) on the day of the mammogram, as these can interfere with the reading.

It's also wise to find a facility with a radiologist who specializes in reading mammograms. This helps improve cancer detection rates, according to a study of 44 mammography facilities by National Cancer Institute researchers. "Patients should ask if there is a radiologist devoting at least 50% of his time to reading mammograms," advises study lead author Stephen Taplin, MD. (Not sure if you need one? Here's the bottom line.)

3. Remove your nail polish before a skin cancer screening

Acral lentiginous melanoma, which accounts for 5% of all melanomas, commonly occurs under nails. If you're sporting a bright, summery polish, your doctor won't see the streaks or pigmentation that can signal a problem, says New York University dermatologist Anne Chapas, MD.

Related: What Your Nails Say About Your Health

4. Ask for numbing cream when you get a colposcopy

This test, given after you get an abnormal result on a Pap, lets your doctor examine your cervix more closely and biopsy any cells that need further inspection. To make the procedure more comfortable, ask your doctor to apply some benzocaine gel to numb the area before the exam. Any soreness afterward is minor for most women, but don't have sex or use tampons for at least a week. Wear a sanitary pad, because spotting or a dark discharge is normal for a few days. You can usually resume everyday activities immediately.

5. Use lube for 2 weeks before your Pap test

If you're in menopause or prone to vaginal dryness, a Pap may be more painful, says Prevention advisor and Yale ob-gyn Mary Jane Minkin, MD. Use a vaginal moisturizer like Replens three times a week throughout the 2 weeks before the test to make it more comfortable. Stop using 3 days before the exam, so it doesn't obscure results.

Also, watch the calendar to keep your smear clear. For a more accurate reading, it's best to schedule your test when you're not menstruating.

6. Skip that indulgent pasta dinner before a cholesterol draw

Even if you fast the night before, eating high-starch or fatty meals in the 3 days leading up to a lipid test can raise triglycerides (another type of blood fat) and may affect LDL readings, says Dr. Samaan.

Another time not to schedule your visit: after holidays like Thanksgiving or a decadent vacation. "I definitely see higher numbers around the holidays, so try to wait a couple of weeks after a big feast before getting your cholesterol checked," she recommends.

Need more cholesterol-busting tips? Add these 12 ridiculously heart-healthy foods into your diet.

7. Don't drink liquids before an MRI

Avoid drinking, especially coffee, for at least 1 hour before the test. The procedure requires you to lie still for up to an hour. Interrupt it for a bathroom break and you'll have to start all over. "An MRI itself creates anxiety, which can heighten your urge to urinate," says Jonathan Charney, MD, an assistant clinical professor of neurology at Mount Sinai School of Medicine.

8. Book an AM appointment for a colonoscopy

The rate of polyp detection is significantly higher when tests are done earlier in the day, possibly because physicians aren't fatigued. The quality of bowel preparation--the nasty stuff you have to drink to eliminate fecal matter so your doctor can get a clearer view of your colon--is also better during morning screenings.

To ease drinking the bowel preparation, which can be the toughest part of the colonoscopy, ask your doc for a "low volume" prep, which is half the amount previously required for cleansing, suggests Carole A. Burke, MD, director of the Center for Colon Polyp and Cancer Prevention at the Cleveland Clinic. You can also request a "split-dose" regimen. Research shows that taking a dose both the night before and a few hours prior to the procedure results in a cleaner colon, too, so polyps are more likely to be detected.

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