Instructions to prepare for a laboratory test

Blood tests

Several factors, such as food, coffee and alcohol intake, medication, smoking, physical activity, and time of the day may affect test results. However, most tests can be performed at any time of the day, allowing for a light meal and medication to be taken normally.

  • Avoid heavy physical exercise, alcohol intake and smoking the day before sample collection. Sitting in the laboratory for 15 min prior to sample collection is recommended in order to stabilize the blood circulation.
  • Some tests for hormone measurements (TSH and testosterone, e.g.) should be taken preferably before noon, because hormone secretion follows a diurnal variation.
  • If concentrations of medicines are to be analyzed, you should not take the medications before sample collection. In such cases your doctor will instruct you specifically.

Fasting blood specimen

Fasting specimens (fP-Gluc for fasting plasma glucose, e.g.) are collected before noon after an overnight fast.

  • During the day before specimen collection you can eat and drink normally avoiding, however, alcoholic drinks. During the fast of 8 to 12 hours you are not allowed to eat or drink - some water is allowed.
  • In the morning of sample collection you are allowed to drink one glass of water.

Urine specimens

Avoid abundant drinking prior to specimen collection.

  • Collect the sample in the morning or when at least 3-4 hours have passed since the last urination. Some analyses require morning urine that has been taken immediately after waking up.
  • Urine for a pregnancy test should be collected when the period is approximately one week delayed.
  • In case you prefer taking the specimen at home you will get the instructions and specimen containers at the laboratory.

Please, discuss with your physician, if you cannot follow these instructions.
You may book a laboratory appointment at our website.

Specialists and locations

Jaana Alatalo
Birgit Asell-Johansson
Päivi Gummerus
Susanna Heikka
Laboratoriohoitaja, vastaanottosihteeri
syyskuu 2021viikko 38