Medically reviewed by Isabel Casimiro, MD, PhD A TSH test measures the level of thyroid-stimulating hormone in your blood. Abnormal TSH levels typically indicate a problem with your thyroid, like ...

Your doctor will order a calcium blood test as part of a routine exam or if you're having certain symptoms. Here's what you need to know.

Learn what happens during an ESR test, how to interpret your results, and why this simple blood test remains a crucial tool for detecting inflammation.

Maintaining proper sodium levels in your blood is critical to health. Learn about the symptoms of low sodium, sodium blood tests, and normal sodium levels.

Doctors use a simple blood test to determine typical or atypical CO2 levels in the body. Learn about the CO2 blood test, and how to interpret the results, here.

Phlebotomy is when someone uses a needle to take blood from your vein. It’s also called a blood draw or venipuncture. WebMD explains the process, risks, and side effects.

Thyroid function tests measure how well your thyroid gland is working. Learn how the tests work and how to understand the results.

The test, which consumers can order on their own, measures a protein linked to Alzheimer’s called amyloid beta. But it can’t diagnose cases, and the results may be needlessly stressful.

During venipuncture (blood draw), the phlebotomist (blood collector) inserts a needle through the skin into a vein and a small amount of blood is collected and transferred into a test tube.

A C-reactive protein (CRP) test to is used to check the levels of this protein in the blood. Many conditions can elevate CRP levels, including lupus. Learn more here.

Learn about different types of blood tests, how to prepare for a blood test, and how tests help diagnose and manage conditions like diabetes and heart disease.

Some people feel faint during a blood draw due to the sudden drop in their heart rate and blood pressure from pain or the ...