Doctor-Reviewed Health Guides: Conditions, Procedures & Health News

An ultrasound, also called sonography, is a noninvasive imaging test that uses high-frequency sound waves to create real-time pictures or video of organs and soft tissues inside the body. It's used during pregnancy, to diagnose conditions and to guide procedures. It does not use radiation, takes 30 minutes to an hour, and scans over the skin are painless.

A Pap smear, also called a Pap test, is a quick screening test that collects cells from your cervix so a lab can look for abnormal or precancerous changes. It finds cell changes early, before they turn into cervical cancer, and can also pick up some infections and inflammation. Most people start screening at age 21.

An angiogram (angiography) is a minimally invasive test that uses X-ray images and an injected contrast dye to show how blood flows through the arteries or veins and where they are blocked or narrowed. A blockage can often be treated during the same procedure. Complications happen in less than 1% of cases.

An HIV test shows whether you have the human immunodeficiency virus (HIV), which attacks the immune system. It uses a blood sample or an oral fluid swab, and some rapid tests give a result in 20 minutes. Everyone ages 15 to 65 should be tested at least once, and a positive result needs a second test to confirm it.

An antibody test, also called a serology test, is a blood test that looks for antibodies, proteins the immune system makes to fight viruses, bacteria and allergens. A positive result shows past exposure to an infection or a response to a vaccine, not the germ itself. Providers use it for COVID-19, other infections, autoimmune diseases and allergies.

A cardiac CT scan (heart CT) uses X-rays taken from many angles to build detailed 3D images of the heart, its major blood vessels and nearby structures. It can show plaque and calcium in the coronary arteries. A calcium score of 0 means no calcium was seen in the coronary arteries and a low heart attack risk.

A biopsy is a procedure that removes a sample of tissue, cells or fluid so a pathologist can examine it for disease. Providers use biopsies to diagnose and monitor conditions and to plan treatment. Biopsies aren't only for cancer: they can diagnose inflammation, infections and immune conditions. Results can take a few hours to more than a week.

NIPT (noninvasive prenatal testing) is a screening blood test in pregnancy that checks fetal DNA in the pregnant person's blood to estimate the chance of chromosome conditions such as Down syndrome, trisomy 18 and trisomy 13. It can be done from 10 weeks and carries no risk to the pregnancy. A high-chance result is confirmed with a diagnostic test.

A complete blood count (CBC) is a blood test that measures the number and size of red blood cells, white blood cells and platelets, plus hemoglobin. Providers use it in routine checkups, to look into symptoms such as tiredness, fever, bruising or bleeding, and to monitor conditions. It can detect anemia, infections and blood cancers. No fasting is needed.

Pulse oximetry is a painless test that measures the oxygen level in the blood and the heart rate using a clip on the fingertip. A normal oxygen level is 95% to 100% for all ages. Contact a provider if your reading is 92% or lower at home, and get medical help right away if it's 88% or lower.

MCH, or mean corpuscular hemoglobin, is a value on a complete blood count (CBC) that measures the average amount of hemoglobin in each red blood cell. The normal adult range is 27 to 33 picograms per cell, though labs vary. Low MCH often points to iron deficiency or thalassemia, while high MCH points to low vitamin B12 or folate.

An A1C test is a blood test that shows the average blood sugar (glucose) level over the past three months. Providers use it to detect prediabetes, help diagnose Type 2 diabetes and monitor treatment. An A1C below 5.7% is normal, 5.7% to 6.4% signals prediabetes, and 6.5% or higher usually indicates diabetes. You don't need to fast.

The Glasgow Coma Scale (GCS) is a bedside tool used to measure how conscious a person is. It scores eye opening (1 to 4), verbal response (1 to 5) and motor response (1 to 6), for a total of 3 to 15. A score of 15 means fully awake and oriented, while 8 or lower generally means a coma.

A creatine kinase (CK) test is a blood test that measures creatine kinase, an enzyme found mainly in the skeletal muscles and heart. When muscle, heart or brain tissue is damaged, it leaks CK into the bloodstream, so a high level usually points to recent muscle damage. Providers use it to diagnose and monitor muscle diseases, injuries and inflammation.

A colonoscopy is an exam of your large intestine, including the colon, rectum and anus, using a long, thin, flexible tube with a light and camera. Doctors use it to screen for colorectal cancer, find the cause of bowel symptoms, take biopsies and remove polyps, often in the same visit.

A due date calculator estimates the day your baby is likely to be born. The most common at-home method counts 40 weeks forward from the first day of your last menstrual period, while conception and IVF transfer dates use shorter counts. An early ultrasound from your pregnancy care provider gives the most reliable, official due date.

A pregnancy test checks your urine or blood for human chorionic gonadotropin (hCG), a hormone made by the placenta once a fertilized egg implants in the uterus. A positive result means you are pregnant. Home urine tests are about 99% accurate when used correctly, and they work best after a missed period.

A clinical breast exam (CBE) is a physical check of the breasts done by a provider. They look at the breasts, skin and nipples for changes, then feel the breasts, underarms and collarbone area for lumps or swollen lymph nodes. Most CBEs are normal. A CBE is only one part of breast cancer screening and doesn't replace a mammogram.

Cardiac catheterization (a heart cath) is a minimally invasive procedure in which a cardiologist threads a catheter through a blood vessel in the arm or groin to the heart. With contrast dye and X-rays, it shows blockages in the coronary arteries, checks the valves and heart muscle, and measures pressures and oxygen levels. You stay awake with a sedative.

The erythrocyte sedimentation rate (ESR or sed rate) test is a simple blood test that checks for inflammation in your body. It measures how quickly your red blood cells settle to the bottom of a tall tube of blood; faster settling can mean inflammation. It cannot diagnose a specific condition, needs no preparation and has no side effects.

A lipid panel is a blood test that measures the fats (lipids) in the blood: LDL, VLDL and HDL cholesterol, total cholesterol and triglycerides. Providers use it to screen for and monitor the risk of cardiovascular disease. Ideal adult levels are total cholesterol below 200 mg/dL, LDL below 100 mg/dL, HDL above 60 mg/dL and triglycerides below 150 mg/dL.

A creatinine clearance test checks how well the kidneys filter waste by comparing the creatinine in the urine you pass over 24 hours with the creatinine in a blood sample. It's one way to estimate the glomerular filtration rate (GFR), the main measure of kidney function. It's used less often, mainly when a standard eGFR test may be inaccurate.

An exercise stress test shows how well the heart works when it is pumping its hardest. You walk on a treadmill or pedal a bike, at a pace that gets harder, while an electrocardiogram (EKG) records the heart's electrical activity and your blood pressure, heart rate and oxygen levels are checked. The exercise part lasts 10 to 15 minutes.

A drug test checks a sample of your urine, blood, hair, breath, saliva or sweat for legal or illegal drugs or their breakdown products (metabolites). Urine is the most common sample, and pre-employment screening is the most common reason. A first positive result is usually confirmed with a second, different test, because foods and medicines can cause false positives.