Kaitlin Sullivan is a health and science journalist based in Colorado. She's been part of multiple award-winning investigations into health topics including the international medical device industry ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Psychology Today's online self-tests are intended for informational purposes only and are not diagnostic tools. Psychology Today does not capture or store personally identifiable information, and your ...

You may keep testing positive for COVID-19 even after feeling better for weeks or months. PCR tests are more sensitive and can show a positive result long after you're not contagious. Most people are ...

A mean platelet volume (MPV) test measures the average size of your platelets, which are small blood cells that help with blood clotting. Typical MPV levels range from 7 to 13 femtoliters. High MPV ...

An IgE blood test measures antibodies to help diagnose allergies. High levels of IgE antibodies can mean you have an allergy to something. Your healthcare provide may do additional testing to ...

Psychology Today's online self-tests are intended for informational purposes only and are not diagnostic tools. Psychology Today does not capture or store personally identifiable information, and your ...

What are some common liver tests? A series of blood tests can often find out if the liver is inflamed, injured, or working normally. These tests can also tell the difference between acute and chronic ...

What Is Prostate-Specific Antigen? Your prostate is a gland that makes seminal fluid, which nourishes and transports your sperm when you ejaculate. It's about the size of a walnut and surrounds your ...

Also called a modified Allen test, this is a simple way to measure how well blood flows in your hand. Your doctor may need to check your circulation before they operate on your wrist or a spot nearby, ...