Laboratory Tests 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. Find an Expert Accredited Laboratory Directory College of American Pathologists Children Basic Blood Tests (For Parents) Nemours Foundation Blood Culture (For Parents) Nemours Foundation Tips to Help Children through Their Medical Tests American Association for Clinical Chemistry Specifics Blood Culture Test American Association for Clinical Chemistry Chloride Test American Association for Clinical Chemistry Electrolytes Test American Association for Clinical Chemistry Home Use Tests Food and Drug Administration Lumbar Puncture (Spinal Tap) (For Parents) Nemours Foundation MedlinePlus: A1C National Library of Medicine MedlinePlus: Blood Count Tests National Library of Medicine MedlinePlus: Creatinine MedlinePlus: Liver Function Tests National Library of Medicine MedlinePlus: Metabolic Panel National Library of Medicine MedlinePlus: Urinalysis National Library of Medicine Potassium Test American Association for Clinical Chemistry Sodium Test American Association for Clinical Chemistry Stool Tests Nemours Foundation Venous Sampling Array World of Forensic Laboratory Testing American Association for Clinical Chemistry Related Issues Collecting Samples for Testing American Association for Clinical Chemistry Coping with Test Pain, Discomfort, and Anxiety American Association for Clinical Chemistry Deciphering Your Lab Report American Association for Clinical Chemistry Helping You Identify Quality Laboratory Services Joint Commission How Reliable Is Laboratory Testing? American Association for Clinical Chemistry How You Can Get the Best Results with Home Use Tests Food and Drug Administration Putting New Laboratory Tests Into Practice American Association for Clinical Chemistry Reference Ranges & What They Mean American Association for Clinical Chemistry Test Preparation: Your Role American Association for Clinical Chemistry Tips on Blood Testing American Association for Clinical Chemistry What Do Blood Tests Show? National Heart, Lung, and Blood Institute Where Lab Tests Are Performed American Association for Clinical Chemistry With Home Testing, Consumers Take Charge of Their Health American Association for Clinical Chemistry Start Here Directory of Medical Tests Nemours Foundation Laboratory Tests Food and Drug Administration Understanding Laboratory Tests National Cancer Institute Understanding Your Tests American Association for Clinical Chemistry Videos and Tutorials Getting a Urine Test (For Kids) Nemours Foundation Reference Desk Glossary Food and Drug Administration Index of Glossary Terms American Association for Clinical Chemistry Journal Articles Laboratory Tests Seniors Tips to Help the Elderly through Their Medical Tests American Association for Clinical Chemistry