Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page: https://medlineplus.gov/laboratorytests.html

Laboratory Tests

On this page

Learn More

See, Play and Learn

For You

Summary

Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include:

  • Your sex, age and race
  • What you eat and drink
  • Medicines you take
  • How well you followed pre-test instructions

Your doctor may also compare your results to results from previous tests. Laboratory tests are often part of a routine checkup to look for changes in your health. They also help doctors diagnose medical conditions, plan or evaluate treatments, and monitor diseases.

Start Here

Specifics

Videos and Tutorials

Clinical Trials

Reference Desk

Find an Expert

Children

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.