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 dark line on your home COVID test usually means you're positive and have a lot of the virus. Even if the line is faint, consider the test positive and be cautious to avoid spreading COVID. The test ...

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 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 ...

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 ...

Steffini Stalos, DO, FCAP, is a pathology and lab medicine physician. She is also the chief medical officer of the lab consultancy firm Blood Associates, LLC. Mean corpuscular hemoglobin concentration ...

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 ...

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 ...

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 ...

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 ...