Testing Knowledge
Test Directory
Source-backed test guides: what each test is for, how it is performed, its limitations, and which reviewed products serve it. Personal health questions are answered with knowledge and preparation guidance — not supplier sales.
Ketones in Blood
A ketones in blood test measures the level of ketones in your blood. Ketones are acids that your body makes when it breaks down fat for energy.
Karyotype Genetic Test
A karyotype test is a type of genetic testing . It looks at the size, shape, and number of chromosomes in a sample of cells from your body. Chromosomes are tiny "packages" in your cells that contain your genes . Genes carry information, called DNA , that controls what you look like and how your body works.
Iron Tests
Iron tests measure different substances in the blood to check iron levels in your body. Iron is a mineral that your body needs for growth and development. Your body uses iron to make hemoglobin, a protein in red blood cells. It carries oxygen from the lungs to all parts of the body, Iron is also important for healthy muscles, bone marrow, and organ function. Your body also needs iron to make some hormones .
Intravenous Pyelogram (IVP)
An intravenous pyelogram (IVP) uses x-rays and contrast dye to get clear pictures of the organs of your urinary tract . These are the organs that make urine (pee) and remove it from your body. They include your:
Insulin in Blood Test
An insulin in blood test measures the amount of insulin in a sample of your blood. Insulin is a hormone that your pancreas makes. Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs.
Immunoglobulins Blood Test
An immunoglobulins blood test measures the amount of immunoglobulins in your blood. Immunoglobulins are also called antibodies. Antibodies are proteins that your immune system makes to fight germs , such as viruses and bacteria . Your body makes different kinds of antibodies to fight germs in different parts of the body and at different stages of an infection.
IGF-1 (Insulin-like Growth Factor 1) Test
This test measures the amount of IGF-1 (insulin-like growth factor 1) in your blood. IGF-1 is a hormone , a chemical messenger in your bloodstream that controls the actions of certain cells or organs. IGF-1 manages the effects of growth hormone (GH) in your body. Together, IGF-1 and GH promote normal growth of bones and tissues.
Homocysteine Test
A homocysteine test measures the amount of homocysteine in a sample of your blood. Homocysteine is an amino acid. Amino acids are molecules that your body uses to make proteins.
HIV Viral Load
An HIV viral load test measures the amount of HIV in a sample of your blood. HIV stands for human immunodeficiency virus. The test looks for genetic material from the virus in your blood. These tests are called molecular tests or nucleic acid amplification tests (NAAT or NAT). There are several types of NAAT tests. A PCR test is one type of NAAT that may be used to find HIV.
HIV Screening Test
An HIV test checks a sample of your blood, saliva (spit), or urine (pee) to see whether you are infected with HIV (human immunodeficiency virus). HIV is a virus that destroys certain cells in your immune system . These cells protect your body against diseases from germs , such as bacteria, viruses, and fungi. If you lose too many immune cells, your body will have trouble fighting off infections and other diseases.
Hepatitis Testing
Hepatitis testing uses a sample of your blood to see if you have a current viral hepatitis infection or had one in the past. Hepatitis is a type of liver disease that causes liver inflammation (swelling) and damage. There are several types of hepatitis. Each affects the body and is spread in different ways.
Hemoglobin Test
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is an iron-rich protein in your red blood cells. It carries oxygen from your lungs to the rest of your body. Your cells need oxygen to grow, reproduce, and make energy for you to function. Your hemoglobin levels provide information about the health of your red blood cells. If your hemoglobin levels are abnormal, it may be a sign that you have a blood disorder .
Hemoglobin Electrophoresis
Hemoglobin electrophoresis is a test that measures the different types of hemoglobin in the blood. It also checks for hemoglobinopathy, disorders involving abnormal types of hemoglobin. Hemoglobin is a protein in your red blood cells. It carries oxygen from your lungs to the rest of your body. There are a few different types of normal and abnormal hemoglobin.
Hemoglobin A1C (HbA1c) Test
A hemoglobin A1C (HbA1C) test is a blood test that shows your average level of blood glucose , also called blood sugar, over the past two to three months.
Hematocrit Test
A hematocrit test is a blood test that measures the amount (percent) of your blood that is made up of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. The other parts of your blood include white blood cells (to help fight infection and other diseases), platelets (to help make blood clots to stop bleeding ), and a liquid called plasma.
Heavy Metal Testing
Heavy metal testing includes a group of tests that measures the levels of possibly harmful metals (like lead or mercury ) in your blood, urine, hair, fingernails, stool (poop), or other body tissues.
Haptoglobin (HP) Test
This test measures the amount of haptoglobin in your blood. Haptoglobin is a protein made by your liver to get rid of the hemoglobin outside your red blood cells.
Growth Hormone Tests
Growth hormone (GH) tests are blood tests that check if your body is making a normal amount of GH. Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs. GH, also known as human growth hormone, controls your body's growth. It also helps control metabolism, the process your body uses to make energy from the food you eat. GH is made in the pituitary gland , a small organ at the base of your brain that controls many functions, including growth.
Gram Stain
A Gram stain is a test that checks to see if you have a bacterial infection . A sample is taken from the site of a suspected infection, such as your throat, lungs, genitals, or a skin wound . Gram stains may also be used to check for bacteria in certain body fluids, such as blood or urine.
Gonorrhea Test
A gonorrhea test looks for signs of a gonorrhea bacterial infection in a sample of your urine (pee) or saliva. Gonorrhea is one of the most common sexually transmitted infections (STIs). Anyone can get gonorrhea if they have vaginal, oral, or anal sex with someone who has the infection.
Glucose in Urine Test
A glucose in urine test measures the amount of glucose in your urine (pee). Glucose is a type of sugar. It is your body's main source of energy. Glucose comes from the food you eat. Your body breaks down most of that food into glucose and releases it into your bloodstream. Your blood carries glucose to your cells for energy.
Glucagon Blood Test
This test measures the amount of glucagon in your blood. Glucagon is a hormone made by your pancreas. Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs. Glucagon works with other hormones, like insulin, to help maintain your body's level of blood glucose , also called blood sugar. Glucagon increases your blood glucose levels, while insulin decreases your blood glucose levels.
Globulin Test
Globulins are a group of proteins in your blood. Some globulins are made by your liver. Others are made by your immune system . Globulins play an important role in liver and kidney function, blood clotting, and fighting infection. There are different types of globulins called alpha, beta, and gamma globulins. Tests to measure globulins include:
Gamma-glutamyl Transferase (GGT) Test
A gamma-glutamyl transferase (GGT) test measures the amount of GGT in your blood GGT is an enzyme. Enzymes are proteins that speed up certain chemical reactions in your body. Thousands of enzymes play an important role in all of your body functions. The GGT enzyme is found throughout your body, but it is mainly found in your liver.