Everyday Health Guide

Collects a saliva (oral fluid) sample to detect the recent use of certain drugs (like marijuana, cocaine, or opioids). The person should not eat, drink, chew gum, or smoke for at least 10–15 minutes before providing the sample.

Evaluates semen (the fluid containing sperm) for volume, sperm count, motility (movement), and morphology (shape). Abstinence (avoiding ejaculation) for 2 to 5 days is usually required before providing the sample.

Measures fructose (a sugar that provides energy for sperm movement) in the semen. Low or absent fructose can indicate a blockage in the reproductive tract. Abstinence (avoiding ejaculation) for 2 to 5 days is usually required before providing the sample.

Measures electrolytes (minerals like sodium, potassium, and chloride that help regulate fluid balance and nerve/muscle function). Fasting is usually not required unless part of a larger metabolic panel. A standard blood draw is performed.

SPEP (Serum Protein Electrophoresis, a test that separates proteins in the blood into five major groups) is used to identify the presence of abnormal proteins, such as those produced in multiple myeloma. No fasting is required. A standard blood draw is performed.

Measures SHBG (Sex Hormone Binding Globulin, a protein produced by the liver that carries sex hormones like testosterone and estrogen in the blood). Fasting in the morning is usually recommended. A standard blood draw is performed.

Screens for the presence of Hemoglobin S, which causes sickle cell (an inherited blood disorder where red blood cells become rigid and crescent-shaped) disease or trait. No fasting is required. A standard blood draw or newborn heel prick is performed.

A doctor removes a small sample of skin tissue to examine under a microscope for conditions like skin cancer, rashes, or infections. Local anesthesia (numbing medicine) is injected into the area. The site is covered with a bandage afterward.

A skin prick test (a method to diagnose allergies by introducing a tiny amount of allergen into the top layer of the skin) is performed on the forearm or back. You must stop taking antihistamine medications for several days before the test, as they can block the reaction.

Measures serum sodium (an essential electrolyte mineral that helps regulate the body's water balance and nerve/muscle function). Fasting is usually not required. A standard blood draw is performed.

Culture (growing bacteria in a lab) and Sensitivity (testing which antibiotics will kill the bacteria) are performed on a sputum (thick mucus coughed up from the lower airways) sample. Rinse your mouth with water before coughing deeply to provide a clean sample.

Examines sputum under a microscope or cultures it to detect AFB (Acid-Fast Bacilli, the specific type of bacteria that cause tuberculosis). Early morning samples collected on three consecutive days are often required for the highest accuracy.

Grows and identifies harmful bacteria (like Salmonella or E. coli) in a stool sample that may be causing diarrhea or food poisoning. Collect a small sample in a sterile container provided by the lab, avoiding contamination with urine or toilet water.

Detects excess fat in the stool, which indicates malabsorption (the body's inability to properly absorb nutrients from food). You may be asked to eat a high-fat diet for a few days before collecting a 72-hour stool sample.

Microscopically examines stool for Ova and Parasites (eggs and microscopic organisms that cause intestinal infections). Multiple samples collected on different days may be required to catch intermittent shedding. Avoid taking antacids or anti-diarrheal medications before the test.

Checks stool (feces) for color, consistency, and the presence of parasites, bacteria, or undigested food. Collect a small sample in a clean, dry container provided by the lab. Avoid mixing with urine or toilet water.

Measures sweat chloride (the amount of salt in sweat) to diagnose cystic fibrosis (a genetic disorder affecting the lungs and digestive system). A chemical is applied to a small area of the arm to stimulate sweating, which is then collected. No fasting is required.

Detects non-specific antibodies that the body produces in response to a syphilis infection. No fasting is required. A standard blood draw (venipuncture, drawing blood from a vein) is performed.