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ExaminationhubBefore the examinationPreparation for the examinationPreparing for laboratory examinations

Preparing for laboratory examinations

Laboratories have prepared patient instructions for preparing for laboratory examinations. You can request a written instruction from the doctor or nurse who refers you for laboratory examinations.

A physician’s referral is always required for laboratory examinations in public healthcare services. The referral is most commonly made electronically in the patient information system, or if necessary, as a paper referral. 

Many factors—such as eating, physical exertion, stress, coffee, tobacco, alcohol, and medications (including herbal products and vitamins)—can affect laboratory examinations results. Avoid smoking, alcohol, and strenuous physical activity during the 24 hours prior to sample collection. 

Immediately before sample collection, it is recommended to sit calmly for about 15 minutes to allow blood circulation to stabilize. 

Most laboratory examinations do not require fasting and can be performed at any time of day. Many laboratories are busiest in the morning between 7–9 a.m. If your examinations do not require fasting or morning sampling, it is advisable to avoid this time. Check whether your laboratory allows advance appointment booking to avoid waiting. Accessibility has been considered in the facilities where possible. Please check accessibility in advance with your testing location if needed. 

Following the instructions ensures reliable laboratory results. If you must deviate from the given instructions, inform the sample collector. 

Hint

Please note that this site provides general information about laboratory and imaging examinations. For details on appointment booking, opening hours, and arrival instructions, refer to the website of your healthcare provider. 

    Some laboratory examinations require fasting before sample collection. This means you should not eat for 10–12 hours prior to the examination. During fasting, you may drink a glass of water. 

    Certain laboratory examinations require sample collection at a specific time of day. In these cases, your physician or nurse will instruct you to come to the laboratory at the designated time. 

    Medications can usually be taken as normal before laboratory examinations unless otherwise instructed by your physician. If a blood sample is taken to assess the concentration of a specific medication, take the medication only after the blood sample has been collected, unless your treating physician provides different instructions. The sample collector may ask about your medication use before sample collection. 

    For the examination of cells or bacteria in urine, the urine should remain in the bladder for at least 4 hours before sample collection. This allows the substances being tested to concentrate in the urine, resulting in more reliable test results. 

    If you have received supplies and instructions from the laboratory for collecting a urine sample at home, be prepared to report the time of sample collection and the duration (in hours) that the urine remained in the bladder before collection when you bring the sample to the laboratory. 

    Some urine examinatios require timed collection, where all urine is collected over a specific period. You will always receive separate instructions and supplies for these examinations. 

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    Updated 17.10.2025

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