3 Common Health Screening Tests and Tips

Health screening tests help to detect conditions before symptoms are shown.

Diabetes test (fasting blood glucose test)
You should refrain from consuming food or drink (except water) for 10 to 12 hours prior to the test.
Unlike the cholesterol test, it is uncertain if cutting down on sugar one week prior to a diabetes test will have any effect on the results. for the same reason, it would be unwise to try to “fool” the test, says Dr Goh.
That being said, if you’ve already been diagnosed with diabetes, doctors will use a different blood test than the one used to screen a healthy individual. This test, called the HbA1c test, provides an overall picture of your blood glucose status over the past two or three months and does not require fasting. Impossible to cheat on that one!
Pap smear (test for cervical cancer)
For females, your doctor may suggest that you take a Pap smear during your medical check-up. A Pap smear is a screening test used to detect pre-cancerous or cancerous cells. A nurse or doctor collects cells from the cervix and sends the sample to a laboratory for analysis.
If you’re still menstruating, you should schedule your appointment about two weeks after the start of your menstrual period.
In addition, in the 48 hours prior to the test, you should avoid:
- Sexual intercourse
- Using spermicides, vaginal creams, lubricant jellies, vaginal medications or tampons
Dr Ng Lai Peng, Family Physician, Tampines Polyclinic, SingHealth Polyclinics (SHP), a member of the SingHealth group, says, “These recommendations help to ensure an optimal sample collection. However, a Pap smear can still be performed even if they are not strictly adhered to.”
She adds, “If you experience abnormal vaginal bleeding, you should see your doctor right away; a Pap smear can still be done.”
Colonoscopy (test for colorectal cancer)
Preparation for a colonoscopy should begin three days prior to the test with a “low-residue diet”.
“You should minimise your intake of high-fibre foods such as fruits and vegetables, oats, muesli and brown rice. You can continue eating other foods, such as white rice and meat, as per the usual,” said Assoc. Prof Tang Choong Leong, Head & Senior Consultant, Department of Colorectal Surgery, Singapore General Hospital (SGH), a member of the SingHealth group.
You’ll also need to consume a prep liquid and lots of water to clean out your colon before the screening test. The prep liquid can be taken over 2 days (i.e. half on the night before and half the morning of the colonoscopy) or in one sitting on the morning of the test.
Both ways are equally effective, provided enough water is consumed. Discuss the pros and cons with your doctor first, as the one-day prep may not be advisable in patients with certain conditions, e.g. diabetes.