Everyday Health Guide

Evaluates overall health by measuring red blood cells, white blood cells, and platelets. Fasting is usually not required unless combined with other tests. A standard blood draw is performed.

Measures cortisol (a steroid hormone produced by the adrenal glands in response to stress). Blood must be drawn early in the morning (around 8 AM) when levels are highest. A standard blood draw is performed.

Measures CK (an enzyme found in the heart, brain, and skeletal muscle). Avoid heavy exercise for 2 days before the test. A standard blood draw is performed.

Measures creatinine (a waste product from normal muscle breakdown) to check kidney function. Fasting may be required. A standard blood draw is performed.

Measures D-dimer (a protein fragment produced when a blood clot dissolves in the body). No special preparation is needed. A standard blood draw (venipuncture, drawing blood from a vein) is performed.

Measures DHEA-S (a hormone produced by the adrenal glands that helps produce sex hormones). Fasting is usually not required. A standard blood draw (venipuncture, drawing blood from a vein) is performed.

Detects the NS1 antigen (a specific protein produced by the dengue virus) in the blood. It is most accurate in the first 1–5 days of fever. No fasting is required. A standard blood draw is performed.

Checks for IgM and IgG antibodies (proteins made by the immune system to fight the dengue virus). IgM indicates a recent infection, while IgG indicates a past infection. No fasting is required. A standard blood draw is performed.

Measures the percentage of each type of white blood cell (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) in the blood. No fasting is required. A standard blood draw is performed.

Measures the amount of digoxin (a medication used to treat heart failure and irregular heartbeats) in the blood to ensure it is at a safe and effective level. Blood is usually drawn 6–8 hours after the last dose.

Detects antibodies attached directly to the surface of red blood cells, which can cause them to break down prematurely (hemolysis). No fasting is required. A standard blood draw is performed.

Uses high-frequency sound waves to evaluate blood flow through the arteries and veins in the legs. No special preparation is needed. A gel is applied, and a transducer (a device that sends and receives sound waves) is moved over the skin.

Uses sound waves to create pictures of the heart (echocardiogram) to check its size, shape, and pumping function. No fasting or special preparation is needed. A gel is applied to the chest, and a transducer (a device that sends and receives sound waves) is moved over the skin.

Records the electrical signals of the heart (electrocardiogram) to detect irregular heartbeats or heart damage. No fasting is required. Small sticky patches (electrodes) are placed on the chest, arms, and legs.

Measures electrical activity in the brain (electroencephalogram) to diagnose seizures or sleep disorders. You may be asked to wash your hair the night before and avoid caffeine. Small sensors are attached to the scalp.

Measures electrolytes (minerals like sodium and potassium) excreted in the urine to help determine the cause of abnormal blood electrolyte levels or kidney issues. A 24-hour urine collection is usually required.

Uses a thin, flexible tube with a camera (endoscope) to examine the lining of the esophagus, stomach, and upper small intestine. Fasting for 6–8 hours is strictly required. Mild sedation is usually given.

Measures how quickly red blood cells settle at the bottom of a test tube (erythrocyte sedimentation rate), which indicates inflammation in the body. No fasting is usually required. A standard blood draw is performed.