June 25, 2025An LDH blood test measures lactate dehydrogenase, an enzyme that sits inside almost every cell in your body. That single…
June 25, 2025A CPK blood test measures creatine kinase, an enzyme that leaks out of muscle cells when they are stressed or…
June 25, 2025A troponin blood test measures a protein that leaks into your bloodstream when heart muscle cells are damaged, and it…
June 25, 2025A transferrin blood test measures the protein that carries iron through your bloodstream. It is almost never read on its…
June 25, 2025If your lab report shows a reactive RPR test, the most useful thing to know first is this: a positive…
June 25, 2025Toxoplasmosis IgG and IgM are the two antibodies your lab measured to work out whether you have ever met a…
June 25, 2025A hepatitis C antibody test tells you whether you have ever encountered the hepatitis C virus — not whether you…
June 25, 2025An HBsAg positive result means the hepatitis B virus is present in your body right now. It is also one…
June 25, 2025An HIV blood test looks for traces of the virus in a small blood sample, and the version used in…
June 24, 2025A CA 15-3 blood test measures a protein that breast tissue sheds into the bloodstream. Doctors use it mainly to…
June 24, 2025A CA 125 blood test measures a protein that ovarian and pelvic tissue releases when it is irritated or inflamed…
June 24, 2025The CA 19-9 blood test measures a substance that the pancreas and bile ducts release into the bloodstream, and doctors…
June 24, 2025The CEA blood test measures carcinoembryonic antigen, a protein doctors use mainly to follow colorectal cancer over time rather than…
June 24, 2025An AFP blood test measures alpha-fetoprotein, a protein your body produced in large amounts before you were born and makes…
June 24, 2025A PSA blood test measures prostate-specific antigen, a protein made by your prostate — not by cancer. That distinction matters…
June 20, 2025A 17-hydroxyprogesterone test measures a steroid your adrenal glands make on the way to producing cortisol, and it is the…
June 20, 2025An LH blood test measures luteinizing hormone, a messenger made by the pituitary gland at the base of your brain.…
June 20, 2025An FSH blood test measures follicle-stimulating hormone, the pituitary signal that tells the ovaries to grow eggs and the testicles…
June 20, 2025A PTH blood test measures parathyroid hormone, the hormone that acts as your body's thermostat for calcium. Here is the…
June 20, 2025A cortisol blood test measures the main hormone your adrenal glands release under stress, and its result depends almost entirely…
June 20, 2025Thyroxine-binding globulin (TBG) is the main protein that carries thyroid hormones through your bloodstream, and it explains why a total…
June 20, 2025A free T4 blood test measures the active, unbound form of thyroxine — the main hormone your thyroid gland produces…
June 20, 2025A vitamin K blood test is rarely what your laboratory actually runs. Instead of measuring the vitamin itself, most labs…
June 20, 2025A vitamin E blood test measures alpha-tocopherol, the form of vitamin E your body actually keeps and uses, circulating in…
June 20, 2025A vitamin A blood test measures retinol, the active form of vitamin A circulating in your bloodstream. Laboratories print it…
June 20, 2025A vitamin C blood test measures how much ascorbic acid is circulating in your blood at the moment the sample…
June 20, 2025The vitamin D blood test, printed on your report as 25-OH vitamin D or 25-hydroxyvitamin D, measures how much vitamin…
June 20, 2025A folic acid blood test measures how much vitamin B9 is circulating in your blood, and it is one of…
June 19, 2025A serum amyloid A blood test measures a protein that your liver releases within hours of inflammation starting. If SAA…
June 19, 2025A testosterone blood test measures the amount of testosterone, the body's main androgen (male sex hormone), moving through your bloodstream.…