Brad Reisfeld is a professor of chemical and biological engineering, biomedical engineering, and public health at Colorado State University. Your blood serves numerous roles to maintain your health.

Hematocrit is the percentage of red blood cells in a person‘s blood. A typical hematocrit range in adults is 36–54%. However, age, sex, and health conditions can influence hematocrit levels. Low red ...

Lindsay Modglin is a nurse and professional writer who regularly writes about complex medical topics, as well as travel and the great outdoors. She holds a professional certificate in scientific ...

Free-floating DNA carrying cancerous mutations was detected in blood three years before any other signs of cancer appeared. If approved as a test, doctors might detect cancers sooner and treat them ...

The anion gap blood test measures the acid-base and electrolyte balance in the blood. Results can show whether there is an imbalance in a person’s pH levels, which may be making the blood too acidic ...

A hemoglobin test measures the amount of hemoglobin in red blood cells, which is essential for transporting oxygen throughout the body and carbon dioxide back to the lungs. Normal hemoglobin levels ...

Testing a person’s blood for a type of protein called phosphorylated tau, or p-tau, could be used to screen for Alzheimer’s disease with “high accuracy,” even before symptoms begin to show, a new ...

In July, the US Food and Drug Administration (FDA) approved a new blood-based test to screen for colorectal cancer (CRC). The FDA's approval of Shield (Guardant Health) marks a notable achievement, as ...

A complement C4 (also known as a complement component 4, or simply C4) is a test to measure the level of C4 proteins you have in your blood. These proteins play a role in how your immune system ...

When her husband was undergoing cancer treatment, Cindy Perez of Southwest Ranches, Fla., learned about a new blood test that could help find early cancers. The 50-year-old said she felt fine, but her ...

Following your doctor’s instructions is the most important part of preparing for a blood test. Sleeping well, staying hydrated, and avoiding certain foods and drinks can also provide benefits. Blood ...