Your doctor says everything looks fine, but you still feel terrible. The problem might not be your health but how labs define “normal.” Understanding the difference between normal and optimal could ...

Hemoglobin is a protein in red blood cells. It carries oxygen around your body, delivering it to tissues. Hemoglobin also carries carbon dioxide to the lungs so you can breathe it out. Iron is a part ...

Run-of-the mill? Middle of the road? Typical? The chance that you are correct is vanishingly small. If you're a clinician, like me, you get a LOT of medical questions. While we've all been asked to ...

Professor of Chemical and Biological Engineering, Biomedical Engineering, and Public Health, Colorado State University Your blood serves numerous roles to maintain your health. To carry out these ...

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 ...

What Is a Cortisol Test? A cortisol test measures the level of cortisol in your blood, urine or saliva. Cortisol is a hormone that's important throughout the body for maintaining blood pressure, blood ...

Labs calculate normal by testing everyone who walks through the door, including patients with undiagnosed conditions and chronic diseases. The middle 95 percent becomes the reference range, whether ...