Everyday Health Guide

Measures triglycerides (a type of fat found in the blood). High levels can increase the risk of heart disease. Fasting for 9–12 hours is strictly required. A standard blood draw is performed.

Checks for TB exposure by injecting a small amount of tuberculin fluid just under the skin of the forearm. The injection site must be examined by a healthcare professional 48 to 72 hours later to measure any swelling.

An IGRA (a blood test that checks for TB infection by measuring the immune system's reaction to TB proteins) is more specific than the traditional skin test. No fasting is required. A standard blood draw is performed.

Measures CA 15-3 (Cancer Antigen 15-3, a protein that can be elevated in breast cancer). It is primarily used to monitor treatment response, not for initial screening. No fasting is required. A standard blood draw is performed.

Uses high-frequency sound waves to create pictures of internal organs (liver, kidneys, gallbladder, etc.). Fasting for 6–8 hours is usually required to reduce gas in the stomach, which can block the sound waves. A gel is applied to the skin, and a transducer (a device that sends and receives sound waves) is moved over the abdomen.

A urea breath test (a test where you drink a special liquid and breathe into a bag to detect H. pylori bacteria in the stomach). You must fast for at least 4 hours and stop taking certain acid-reducing medications beforehand.

Measures uric acid (a waste product created when the body breaks down chemicals called purines). Fasting for 4 hours may be recommended. Avoid high-purine foods (like red meat) and alcohol for 24 hours before the test. A standard blood draw is performed.

UACR (a calculation comparing albumin to creatinine in a single urine sample to check for early kidney damage) is highly recommended for people with diabetes or high blood pressure. A random urine sample is collected.

Culture (growing bacteria in a lab to identify them) and Sensitivity (testing which antibiotics will kill the bacteria). Collect a mid-stream clean catch urine sample (urinating a little first, then collecting the middle part of the stream in a sterile cup).

Detects ketones (chemicals produced when the body breaks down fat for energy instead of glucose) in the urine. A random urine sample is collected using a dipstick.

Measures urine pH (a number indicating how acidic or alkaline the urine is, which helps evaluate kidney function and the risk of certain kidney stones). A random urine sample is collected.

Checks the physical and chemical properties of urine, and uses microscopy to look for red blood cells, white blood cells, or crystals. A clean catch mid-stream sample is preferred. No fasting is required.

Measures folate (a B vitamin essential for making red blood cells and DNA, especially important during pregnancy). Fasting for 8 hours is usually recommended. A standard blood draw is performed.

Measures Vitamin B12 (a nutrient that helps keep the body's nerve and blood cells healthy and helps make DNA). Fasting is usually not required, but some labs prefer it. A standard blood draw is performed.

Measures 25-hydroxy vitamin D (the major form of vitamin D found in the blood, used to determine overall vitamin D levels). Fasting is usually not required. A standard blood draw is performed.

Detects antibodies against the bacteria (Salmonella typhi) that cause typhoid fever. It is most accurate after the first week of fever. No fasting is required. A standard blood draw is performed.

Uses a small amount of ionizing radiation (energy waves that can pass through the body to create images) to produce pictures of the heart, lungs, airways, blood vessels, and bones of the chest. You will be asked to stand still and hold your breath for a few seconds. Remove metal jewelry.

Uses a small amount of ionizing radiation to create images of the spine (the backbone) to check for fractures, curvature (scoliosis), or degenerative changes. Remove metal objects. You will be asked to lie down or stand still while the image is taken.