How to Prepare for Tests

How to Prepare for Laboratory Tests

Proper preparation before laboratory testing is essential to ensure accurate and reliable results. Because preparation requirements may vary depending on the type of test or diagnostic panel, following general guidelines and specific instructions is strongly recommended.

For your own benefit, we advise contacting the Customer Service Department before performing any test. Our team can provide clear and detailed instructions tailored to your specific test or panel.

If you are pregnant or suspect that you may be pregnant, please inform our staff upon arrival at the diagnostic center.

Preparing for Blood Tests

Before a blood sample is collected, it is important to follow certain preparation rules to ensure the accuracy of test results. Factors such as fasting, diet, medication, physical activity, and posture can influence laboratory values to varying degrees.

The following recommendations will help simplify the sampling process and improve the reliability of the analysis.

Fasting

For most blood tests, patients are required to fast for at least 8–12 hours before sample collection.

During this period:

• Small amounts of water are allowed.
• Sugary drinks, alcohol, coffee, and smoking should be completely avoided.

These substances can significantly affect blood test results and may lead to inaccurate findings.

Diet

In the days leading up to the blood test, your diet should remain as normal and balanced as possible. Sudden or extreme changes in calorie intake—either excessive or restrictive—should be avoided.

Studies have shown that a drastic reduction in daily calorie intake (for example, 300–600 calories per day) can reduce plasma volume by up to 30%, leading to measurable changes in blood parameters that may affect test results.

Medications

Many medications can influence laboratory test results.

Whenever possible, preparation for blood tests should include reducing or temporarily discontinuing certain medications. This must always be done in consultation with your doctor, and medications should never be stopped without medical advice.

Physical Exercise

Intense or prolonged physical activity can cause temporary changes in enzyme levels and other laboratory parameters.

For this reason:

• Intense exercise should be avoided immediately before blood sampling.
• Physical exertion should also be avoided for 8–12 hours prior to testing.

This recommendation is especially important for urine tests involving creatinine determination.