Common Blood Test Names and Meanings

Blood tests are part of routine health screenings and have many purposes, including checking organ function and immune system activity, diagnosing chronic diseases like diabetes, and helping prevent complications from surgery. Needing a blood test doesn’t mean your healthcare provider suspects something is wrong. Often, these tests confirm that your health is in good shape.

Basic Metabolic Panel: Chem 7

Also known as a blood chemistry, chemistry panel, or basic metabolic panel, this test examines essential enzyme levels and checks kidney function.

The glucose level in the blood is also measured to check if further diabetes testing is necessary.

These seven tests are included:

• Blood urea nitrogen (BUN)
• Serum glucose
• Creatinine
• Carbon dioxide (CO2)
• Serum chloride
• Serum sodium
• Serum potassium

Complete Blood Count (CBC)

A complete blood count (CBC), looks at the different cells that make up whole blood. A CBC can inform the doctor if the body is making the appropriate number of each type of cell, and it can also reflect signs of a current or recent infection, bleeding, or clotting issues.

After surgery, the doctor may order this test to see if a blood transfusion is warranted or to evaluate for infection.

A CBC includes:

• White blood cell count (WBC): WBCs, also called leukocytes, help your body fight infection.
• Red blood cell count (RBC): Also called erythrocytes, RBCs carry oxygen to your tissues.
• Platelet count: Also known as thrombocytes, platelets form clots to stop bleeding.
• Hemoglobin: This protein in red blood cells delivers oxygen to your tissues.
• Hematocrit: This is the volume percentage of red blood cells in the blood.

An H&H is similar to a CBC but only looks at the hemoglobin and hematocrit levels.

Heart Disease and Cholesterol

Most healthy adults should have their cholesterol checked every four to six years. You may need these tests more frequently if you have a family history of heart disease or other risk factors.

A cholesterol screening is a blood test that checks the following levels:

• LDL cholesterol: Also known as the “bad” cholesterol
• HDL cholesterol: Also known as the “good” cholesterol
• Triglycerides: A type of fat in the blood, higher levels of which increase the risk of heart disease
• Total cholesterol: A measurement of LDL, HDL, and triglycerides combined

Other cardiac blood tests that may be ordered include:

• Lipoprotein A (Lpa): High levels of Lp(a) increase your risk of heart attack and stroke.
• C-reactive protein (CRP): This protein is produced by the liver in response to inflammation. High levels of CRP often indicate atherosclerosis—the buildup of cholesterol plaque in arterial walls.
• Homocysteine: Too much homocysteine, an amino acid, raises your risk of heart attack or stroke. This test is often ordered for people who have a family history of heart disease but no other known risk factors.

Thyroid Function Tests

Your healthcare provider may order one or more thyroid tests if you have signs of an underactive or overactive thyroid gland.

The thyroid stimulating hormone (TSH) test is typically done first. TSH is made in the pituitary gland and tells the thyroid gland how much T4 (thyroxine) and T3 (triiodothyronine) hormones to make.

High TSH typically means you have hypothyroidism. If you get this result, you may be given a T4 blood test to confirm a diagnosis of hypothyroidism. Conversely, low TSH typically means you have hyperthyroidism. To confirm this diagnosis, your provider may order a T3 blood test.

Some providers order both a T4 and a T3 test to rule out other possible causes of an abnormal TSH test. For example, your thyroid hormone levels may be higher if you are pregnant or taking corticosteroids to treat another medical condition.

Prostate Screening

Prostate screening involves a blood test called a prostate-specific antigen (PSA) test. PSA is a hormone made in the prostate gland by both normal and cancer cells. Most PSA is in semen, but small amounts are also found in blood.

Higher levels of PSA mean there is a higher chance of having prostate cancer. Most males who do not have prostate cancer have PSA levels under 4 ng/mL (nanograms per milliliter). PSA levels between 4 and 10 are considered the borderline range. About one in four people who fall within this range have prostate cancer.

Hormone Levels

Blood tests are commonly done to diagnose issues related to reproductive hormones, particularly estrogen (also called estradiol) and testosterone.

Females may need an estrogen blood test if their provider suspects an issue related to puberty, menstruation, pregnancy, or menopause. The test may be done to see if a female is responding to fertility treatment. It may also be ordered for males experiencing late puberty or abnormal breast growth.

In males, a testosterone blood test may be done to help diagnose infertility, erectile dysfunction, low libido, and more. In females, a testosterone blood test can help diagnose the cause of excessive hair growth (hirsutism), abnormal menstrual periods, hair thinning, and more.

A progesterone blood test is often ordered for females who experience repeated miscarriages, or to determine the risk of miscarriage in early pregnancy. Progesterone plays a crucial role in pregnancy.

Diabetes

If you have diabetes or your healthcare provider suspects you might, they will likely order one or more blood tests to check your blood sugar (glucose). Blood tests will confirm a diagnosis of prediabetes, type I diabetes, type II diabetes, or gestational diabetes.

The different types of blood tests for analyzing blood sugar include:

• Glucose screening test: You will be asked to drink a liquid containing glucose and will then have your blood drawn one hour later. This test is normally done in pregnant people between 24 and 28 weeks of pregnancy.
• Glucose tolerance test: You will need to fast overnight before taking this test. Your blood will be drawn before drinking a glucose-containing liquid, and then again one to three hours after.
• Fasting blood sugar test: This test is a measurement of your blood sugar after fasting (not eating) overnight.
• Hemoglobin A1C (HbA1c) test: The HbA1c is a test that shows what your average glucose level was over the previous two to three months. People with diabetes should get this test at least twice per year.

If your healthcare provider suspects you have type 1 diabetes, your blood may also be tested for specific antibodies that are often present in people with type 1 diabetes, but not in those with type II.

Nutritional Deficiencies

Severe nutritional deficiencies can lead to a number of problems, including intellectual impairments, poor wound healing, poor growth, and perinatal complications, as well as a higher risk of death due to all causes.

Blood tests can be used to detect deficiencies in the following vitamins and minerals:

• Magnesium
• Iron
• Folate
• Vitamin B12
• Vitamin D

Pregnancy

If you have tested positive for pregnancy with a urine test, your provider will order a pregnancy blood test. The test measures levels of quantitative human chorionic gonadotropin (hCG), a hormone that is produced in the body during pregnancy.

An hCG test can detect pregnancy as soon as 10 days after conception. It can also help diagnose abnormal pregnancies, such as:

• Ectopic pregnancies, in which the fertilized egg implants and grows outside of the main uterine cavity
• Molar pregnancies, in which a tumor develops in the uterus as a result of an inviable pregnancy
• Possible miscarriages

The hCG test is also performed to screen for Down Syndrome.

PT, PTT, and INR

These tests, known collectively as a coagulation panel, look at the ability of your blood to clot. Disordered clotting ability can cause problems in surgery, during which bleeding is often expected.

If the result shows impaired clotting ability, it may be necessary to delay surgery to prevent significant bleeding during the procedure. This test may also be used to monitor blood-thinning medications, such as warfarin.

Liver Enzymes

Liver function studies, also known as LFTs, are done to determine if the liver is functioning normally. Because the liver plays a role in removing anesthesia from the bloodstream and normal blood clotting, it’s essential to know if it’s functioning normally prior to the procedure. Elevated numbers can indicate liver damage or poor liver function.

An additional test, called a GGT, may be added to the liver panel. This test can indicate that there is damage to the liver or surrounding ducts, but does not specify what type of damage is present.

A typical liver function study includes:

Arterial Blood Gas

An arterial blood gas, commonly called an ABG, looks at how the respiratory system is functioning and how much oxygen is in the blood. This test requires blood from an artery, which is fully oxygenated by the lungs and is typically drawn from the radial artery in the wrist.

Abnormal results may indicate that the blood is low in oxygen, that the patient is breathing too much or too little (on a ventilator during the surgical procedure), or that they need additional oxygen.

The ABG is typically performed at least once a day when the patient is on a ventilator for an extended period of time. The results are used to determine if any changes in ventilator settings are necessary.

If the patient is in ICU, a special IV called an arterial line may be placed to make drawing arterial blood easier, particularly when it’s being done frequently.

A typical ABG includes:

• pH: The acid/base balance of arterial blood
• PC02: How much carbon dioxide is in the blood
• PO2: How much oxygen is being concentrated in the blood
• HCO3: Bicarbonate levels may indicate kidney function issues
• O2: How much oxygen is available for the tissues of the body to use

ABG interpretation is very challenging and is typically done by physicians or providers.

ABO Typing

ABO typing is the medical term for determining the patient’s blood type. This is done prior to surgery, so blood can be given in the operating room if necessary. Most surgeries do not require a blood transfusion, but some procedures, such as on-pump heart bypass surgery, routinely require the administration of blood.

You may be asked to sign a consent form for the administration of blood before your surgery, even if a transfusion is not a routine part of the procedure, in case the need arises.

Blood Culture and Sensitivity

A blood culture is a process where a small sample of your blood is drawn into a bottle of sterile culture medium that “feeds” bacteria. The sample is kept warm, and after a few days, it is checked to see if bacteria is growing. If so, it is likely that the same bacteria is growing in your blood.

The bacteria is then exposed to different antibiotics to see which antibiotic is the most effective for treating your infection. This is a scientific way to choose the best antibiotic for your infection without giving you multiple antibiotics and hoping one works well.