Plain-English guides to common laboratory tests, what they measure, why clinicians may order them, and why results should be interpreted with clinical context.
Phosphate Blood Test Explained A phosphate blood test measures the amount of phosphate in the blood. Phosphate contains the mineral phosphorus, so the test may also be called a phosphorus test. MedlinePlus explains that phosphate contains phosphorus and that phosphate testing may also be called phosphorus testing. Phosphate is not just a diet-related number. It … Read more
Calcium Blood Test Explained A calcium blood test measures how much calcium is circulating in the blood. It does not measure how much calcium is stored in the bones. This distinction matters because many people assume a calcium blood test is a bone-strength test, but it is not. Cleveland Clinic explains that around 99% of … Read more
Procalcitonin Test Explained A procalcitonin test measures the amount of procalcitonin, often shortened to PCT, in the blood. Procalcitonin is a substance that can rise during serious bacterial infection and sepsis. It is most often used in hospital, emergency, or intensive care settings. Testing.com explains that procalcitonin can rise significantly in systemic bacterial infections and … Read more
ESR Blood Test Explained ESR stands for erythrocyte sedimentation rate. It is also called sed rate or sedimentation rate. The ESR blood test measures how quickly red blood cells settle at the bottom of a tube over a set period of time. A faster-than-expected ESR can suggest inflammation, but it does not show the exact … Read more
Reticulocyte Count Explained A reticulocyte count is a blood test that measures immature red blood cells in the blood. Reticulocytes are young red blood cells that have recently been released from the bone marrow. They usually mature into fully developed red blood cells within about one to two days. This makes the reticulocyte count useful … Read more
Serum protein electrophoresis, often shortened to SPEP or serum electrophoresis, is a blood test that separates proteins in the liquid part of blood into groups or bands. Instead of giving only one total protein number, it shows a pattern of protein fractions. This test is often used when healthcare professionals need to look more closely … Read more
A blood film examination is a laboratory test where a thin layer of blood is spread onto a glass slide, stained, and examined under a microscope. It is also called a blood smear, peripheral blood smear, peripheral blood film, manual differential, or blood cell morphology review. A blood film gives visual information about red blood … Read more
A urea blood test measures the amount of urea in the blood. Urea is a waste product made when the body breaks down protein. It is carried in the blood to the kidneys, where it is filtered and removed in urine. In many UK-style blood test reports, the result is called urea. In many US … Read more
Amylase and lipase are digestive enzymes that may be measured in blood when healthcare professionals are assessing the pancreas or related digestive problems. They are often discussed together because both can rise in pancreatic disease, including pancreatitis. However, they are not the same enzyme, and they do not always rise for the same reasons. Amylase … Read more
LDH stands for lactate dehydrogenase. An LDH test measures the amount of lactate dehydrogenase in a blood sample, although LDH can also be measured in some body fluids in specific clinical situations. LDH is an enzyme found in many tissues of the body, with large amounts found in muscles, liver, kidneys, and red blood cells. … Read more