How to prepare for laboratory examinations

Lots of information about health can be determined by means of laboratory examinations, ranging from blood cholesterol levels to vitamin levels or the functioning of internal organs. We always recommend laboratory examinations based on instructions given by your attending physician, but you can also come in for laboratory tests without a doctor’s referral.

Always determine well in advance before any laboratory tests whether you must prepare for the examination in advance. Follow the instructions to ensure the reliability of test results. Inform the person taking the sample if you failed to follow any instructions. When you come to the examination please be prepared to identify yourself with photo ID.

Please contact SYNLAB’s customer service for further information, tel. +358 10 326 3260.

Preparing for blood tests


See the list of test requiring fasting here.

  • If the test requires fasting: Do not eat or drink anything for 10–12 hours before the blood test. If necessary, you can have a glass of water.
  • Avoid drinking alcoholic beverages for 24 hours before the test.
  • Do not smoke in the morning before the test.
  • Do not drink caffeinated drinks (coffee, tea etc.) before the test.
  • Diabetics must follow their physician’s instructions about fasting.
  • Infants are not required to fast. Small children should fast, if possible, unless otherwise instructed by the physician.
  • We recommend that any blood tests requiring fasting are taken at 8–10 a.m.
  • Examinations requiring fasting usually have a small letter f in front of them, such as fP-Gluk.

If fasting is not required for the examination, you may eat a light meal before the test.

Physical strain

  • You should sit down for at least 15 minutes before the sample is taken so that your circulation has a change to stabilise.
  • Avoid sweaty exercise on the morning of the examination.


  • Avoid taking herbal remedies and vitamins on the morning of the test.
  • Follow your physician’s instructions about taking your medication.
  • In case of drug concentration tests, however, you should usually not take the medication in question before the test is taken.
  • You can check the harmful effects of your medications on the substance being measured from the “Lääkkeen vaikutus laboratoriotutkimuksiin” database (in Finnish).
  • Thyroid tests, TSH and T4-V: If you are using thyroxine medication, the test is taken before the thyroxine tablets.

Time of day

Some examinations (such as hormone measurements) are done at a certain time of day.

  • The concentration of TSH varies during the day, and we therefore recommend taking the sample at 8—12 a.m.
  • Shift work and timing of tests: We recommend that tests are taken from 8 a.m. to 6 p.m. Tests should, however, be taken within a couple of hours after you wake up.

Examples of examinations requiring testing at a specific time of day:

  • S-TSH is taken before 12 noon
  • S- Korsol is taken at 7–9 a.m.
  • S- Testo is taken before 12 noon
  • S-Testo-V is taken before 10 a.m.
  • S-TestoVL is taken before 12 noon
  • fS-Fe, iron is taken in the morning after fasting. Any oral iron medication used must be interrupted two days before the test.

Preparing for other laboratory examinations

Specimens taken at home, such as urine and stool specimens, must be taken according to separate instructions in specimen containers provided by the SYNLAB laboratory. Do not use your own containers.

  Urine specimen

  • Urine tests (midstream specimen of urine): Avoid eating and drinking during the night. You may drink a glass of water in the morning. Do not urinate for 4–6 hours before collecting the specimen.
  • For specimens used for the testing of infections, urine must remain in the bladder for 4–6 hours or as long as possible.
  • Urine cytology test (U-Syto-1): Approximately two hours before collecting the specimen, empty the bladder and drink 0.5–1.0 litres of water. The urine specimen is always collected in the laboratory.

Follow the instructions provided in case of all other urine specimens. For 24-hour urine sample examinations (DU, cU), for example, our SYNLAB laboratories provide detailed instructions and tools for collection.

Specimen from the throat

Do not eat or drink for 30 minutes before the specimen is taken. In addition, avoid using products which flush or disinfect the throat (such as mouth wash, lozenges, chewing gum).

ECG test or heart film

The ECG test or heart film is only available in some of our locations. Check the availability of heart filming in the location of your choice from our customer service. The ECG test takes approximately 20 minutes.

Patient instructions

Preparing for examinations

Cancelling an examination appointment

If you are unable to come, you may cancel your appointment by calling the appointment number or in your online Health Folder. You cannot cancel an appointment by e-mail.

We charge EUR 30 of no shows or appointments cancelled less than 24 hours before the examination.