Your blood is a delicate mixture. Researchers and clinicians often use blood to learn what's going on inside our bodies, in part because siphoning off a tube of blood is easier and less painful than ...

Running extreme distances may strain more than just muscles and joints. New research suggests ultramarathons can alter red blood cells in ways that make them less flexible and more prone to breakdown, ...

Red blood cells carry oxygen from the lungs around the body. They then carry carbon dioxide from around the body back to the lungs. These cells are an important component of blood. However, a range of ...

Scientists have long known that people living at high altitudes, where oxygen levels are low, have lower rates of diabetes ...