Everyday Health Guide

Measures EPO (a hormone produced by the kidneys that stimulates the bone marrow to make red blood cells). Fasting is usually not required. A standard blood draw is performed.

Measures estradiol (the primary form of estrogen in the body, important for reproductive health and bone strength). For women, it is often tested on specific days of the menstrual cycle. A standard blood draw is performed.

A genetic blood test that checks for the Factor V Leiden mutation, which increases the risk of developing abnormal blood clots. No fasting is required. A standard blood draw is performed.

Measures insulin (a hormone that regulates blood sugar) after fasting (not eating or drinking anything except water) for 8–12 hours. It helps detect insulin resistance. A standard blood draw is performed.

Measures calprotectin (a protein released by white blood cells in the intestines during inflammation) in the stool. It helps distinguish between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). A small stool sample is collected at home.

Detects occult (hidden) blood in the stool that cannot be seen with the naked eye. You may be asked to avoid red meat, certain vegetables, and vitamin C for a few days before the test. A small stool sample is collected at home.

Measures ferritin (a protein that stores iron in your cells) to check for iron deficiency anemia or iron overload. Fasting for 8–12 hours may be recommended for accuracy. A standard blood draw is performed.

Measures fibrinogen (a protein produced by the liver that helps blood clot). Fasting may be required depending on the lab. A standard blood draw is performed.

Measures FSH (a hormone that regulates the development of eggs in women and sperm in men). For women, it is often done on specific days of the menstrual cycle. No fasting is usually required. A standard blood draw is performed.

Measures Free T4 (the active, unbound form of the thyroid hormone thyroxine) to check how well the thyroid gland is working. Fasting is usually not required, but some medications may need to be paused. A standard blood draw is performed.

Measures free testosterone (the active form of the hormone that is not bound to proteins in the blood). Blood is best drawn in the morning when levels are highest. A standard blood draw is performed.

Measures GGT (an enzyme found mainly in the liver and bile ducts). Fasting for 8 hours is usually required, and you should avoid alcohol for 24 hours before the test. A standard blood draw is performed.

Measures gastrin (a hormone that stimulates the stomach to produce acid). Fasting for 8–12 hours is usually required, and certain acid-reducing medications may need to be stopped beforehand. A standard blood draw is performed.

Calculates eGFR (an estimate of how well the kidneys are filtering waste from the blood) based on your creatinine level, age, and gender. Fasting may be required. A standard blood draw is performed.

Checks how your body processes sugar. You must fast for 8 hours. A fasting blood sample is taken, then you drink a sugary liquid, and blood is drawn again after 1 or 2 hours.

Measures HbA1c (a form of hemoglobin that is chemically linked to sugar), showing your average blood sugar levels over the past 2 to 3 months. No fasting is required. A standard blood draw is performed.

A laboratory test that uses a special dye to quickly identify the type of bacteria present in a sample (like sputum, urine, or wound fluid) and whether they are Gram-positive or Gram-negative. No patient preparation is needed; the lab handles the sample.

Measures growth hormone (a hormone that promotes growth in children and maintains tissues in adults). Fasting and resting for 30 minutes before the blood draw are usually required, as GH levels fluctuate. A standard blood draw is performed.