Frequently Asked Questions

Below you will find answers to the most frequently asked questions people have about laboratory tests.

1. Do I need to fast before having blood tests?
Yes, for tests such as glucose, lipids, iron, etc., an 8–12 hour fast is required. You can drink water.

2. I take medication in the morning. Should I take it before the blood draw?
Ask your doctor or the laboratory. For some tests (e.g., hormonal, thyroid), the timing of medication intake plays a role.

3. Can I drink coffee in the morning before the test?
No. Coffee (even without sugar) can affect the results. Only water is allowed.

4. For a urinalysis, do I need to bring the urine from home?
Yes, ideally, the collection is done at home, early in the morning, and the sample reaches the laboratory within 1 hour.

5. Does the blood draw hurt?
Not much. It's a short procedure that lasts a few seconds. Sterile, single-use needles are used.

6. When will I get the results?
Most tests are ready on the same or the next day. Some more specialized ones may take longer.

7. Do I need to make an appointment?
No, but it's a good idea to call in advance, especially if it's for a large panel of tests or for tests that require special preparation (e.g., glucose tolerance test, hormone tests).

8. Does smoking affect test results?
It is preferable to avoid smoking before the blood draw. For example, growth hormone doubles in 30 minutes, while glucose increases in 10 minutes and the increase lasts for 1 hour. In chronic smokers, an increase in red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), MCV, and MCH is observed. White blood cells often increase by up to 35%, and an increase is also observed in all subpopulations, except for eosinophils, which are reduced.

9. Does menstruation affect my tests?
A few days before and during menstruation, blood iron (Fe) levels drop. Also, cholesterol decreases during ovulation.

10. Can I have blood tests done in the afternoon?
It depends on the blood test you need to have. If it's for a general check-up, a morning blood draw (after an 8-hour fast) is preferred. For iron measurement, a morning blood draw is also preferred because serum iron levels drop by 30% to 50% in the afternoon.

11. The last time I had blood drawn, my arm bruised at the injection site. Why?
This happens because the blood clot that closes the exit point of the blood took a while to form. Once the needle is out, press firmly with cotton for 1 to 2 minutes and for another minute with a bandage. This time is longer for people who take anticoagulants.

12. What should I do before the blood draw?
Before the blood draw, you should not change your eating habits out of fear of your test results.
A 10-hour fast is recommended before the blood draw.
You can drink water before the blood draw. Your veins will be easier to palpate, and you won't feel dizzy.
Inform your microbiologist about any medication you are taking or any medical conditions you have.

13. I have "thin" veins, and they have trouble finding a vein.
We suggest drinking plenty of water (8-10 glasses/day) 1-2 days before the blood draw, and generally try to exercise your arms as much as possible. Our laboratory's experienced staff and the advanced vein detection system we have promise to change your opinion about blood draws.

14. From what age is it good to have blood tests done?
There is no starting age limit. Usually, the pediatrician recommends a check-up in the first or second year of life.

15. How should I collect a 24-hour urine sample?
A 24-hour or shorter duration (e.g., 12-hour) urine collection is needed in cases where quantitative determinations of certain substances are done for diagnostic purposes or to monitor a function (e.g., measurement of 24-hour protein, electrolytes, hormones). The patient urinates in the morning at 8 a.m. - before breakfast - emptying their bladder well, and this urine is discarded.
From then on, the urine from each urination is carefully collected in the collection container directly or by transfer from the urination container.
The collection container is kept in the refrigerator. In case of nocturia, this urine is also carefully collected. The next day at exactly 8 a.m., the patient urinates again, making sure to empty their bladder well. This is the last sample, and with it, the 24-hour urine sample is complete. The collection containers are provided by the pharmacy. 24-hour urine is unsuitable for culture.