Laboratories

Complete Blood Count (CBC)

Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions such as anemia, infections, clotting problems, blood cancers, and immune system disorders.

Specific types include tests for

  • RBC - the numbers, size, and types of RBC in the blood

  • WBC - the numbers and types of WBC in the blood

  • Platelets - the numbers and size of the platelets

  • Hemoglobin - an iron-rich protein in red blood cells that carries oxygen

  • Hematocrit - how much space red blood cells take up in your blood

  • Reticulocyte count - how many young red blood cells are in your blood

  • Mean corpuscular volume (MCV) - the average size of your red blood cells

The complete blood count (CBC) includes most or all of these. The CBC is one of the most common blood tests.

 

NIH: National Heart, Lung, and Blood Institute

Comprehensive Metabolic Panel (CMP)

A metabolic panel is a group of tests that measures different chemicals in the blood. These tests are usually done on the fluid (plasma) part of blood. The tests provide information about your body's chemical balance and metabolism. They can give doctors information about your muscles (including the heart), bones, and organs, such as the kidneys and liver.

There are two types: basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). The BMP checks your blood sugar, calcium, and electrolytes. The BMP also has tests such as creatinine to check your kidney function. The CMP includes all of those tests, as well as tests of your cholesterol, protein levels, and liver function. You probably need to fast (not eat any food) before the test. Your doctor will tell you how to prepare for the test you are having.

 

NIH: National Institutes of Health

Glucose Exam

Blood sugar, or glucose, is the main sugar found in your blood. It comes from the food you eat, and is your body's main source of energy. Your blood carries glucose to all of your body's cells to use for energy.

Diabetes is a disease in which your blood sugar levels are too high. Over time, having too much glucose in your blood can cause serious problems. Even if you don't have diabetes, sometimes you may have problems with blood sugar that is too low or too high. Keeping a regular schedule of eating, activity, and taking any medicines you need can help.

If you do have diabetes, it is very important to keep your blood sugar numbers in your target range. You may need to check your blood sugar several times each day. Your health care provider will also do a blood test called an A1C. It checks your average blood sugar level over the past three months. If your blood sugar is too high, you may need to take medicines and/or follow a special diet.

 

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Hemoglobin A1C

A1C is a blood test for type 2 diabetes and prediabetes. It measures your average blood glucose, or blood sugar, level over the past 3 months. Doctors may use the A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that people with diabetes do every day.

Your A1C test result is given in percentages. The higher the percentage, the higher your blood sugar levels have been:

  • A normal A1C level is below 5.7 percent

  • Prediabetes is between 5.7 to 6.4 percent. Having prediabetes is a risk factor for getting type 2 diabetes. People with prediabetes may need retests every year.

  • Type 2 diabetes is above 6.5 percent

  • If you have diabetes, you should have the A1C test at least twice a year. The A1C goal for many people with diabetes is below 7. It may be different for you. Ask what your goal should be. If your A1C result is too high, you may need to change your diabetes care plan.

 

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Urine Analysis

A urinalysis is a test of your urine. It is often done to check for a urinary tract infections, kidney problems, or diabetes. You may also have one during a checkup, if you are admitted to the hospital, before you have surgery, or if you are pregnant. It can also monitor some medical conditions and treatments.

A urinalysis involves checking the urine for

  • Its color

  • Its appearance (whether it is clear or cloudy)

  • Any odor

  • The pH level (acidity)

  • Whether there are substances that are not normally in urine, such as blood, too much protein, glucose, ketones, and bilirubin

  • Whether there are cells, crystals, and casts (tube-shaped proteins)

  • Whether it contains bacteria or other germs

NIH: National Institutes of Health

Lipid Panel

A lipid panel is a simple blood test to check your cholesterol levels. Cholesterol is a soft, sticky substance found inside your body. Total cholesterol is made up of three parts: good (HDL) and bad (LDL) cholesterol, as well as triglycerides (a certain type of fat). A lipid panel is an important test because cholesterol can clog your arteries. This can lead to heartdisease and stroke.

The blood test can be done in a doctor’s office, laboratory, or hospital. A nurse or lab technician inserts a needle into a vein in your arm to collect a small sample of blood. Sometimes the blood can be collected through a prick to your finger. Your blood will be collected into a tube and sent to a lab for testing. The results will be sent to your doctor and your doctor’s office will notify you of the results. The test can be done at any time of the day. However, it’s recommended that you fast (have no food or liquid to drink, except water) for 8 to 12 hours before the test. So it’s best to schedule the test for the morning.

 

NIH: National Institutes of Health

Body Mass Index

A good way to decide if your weight is healthy for your height is to figure out your body mass index (BMI). You and your health care provider can use your BMI to estimate how much body fat you have.

Being obese puts strain on your heart and can lead to serious health problems. These include:

  • Arthritis in your knees and hips

  • Heart disease

  • High blood pressure

  • Sleep apnea

  • Type 2 diabetes

  • Varicose veins

HOW TO DETERMINE YOUR BMI

Your BMI estimates how much you should weigh based on your height.

There are many websites with calculators that give your BMI when you enter your weight and height.

You can also calculate it yourself:

  • Multiply your weight in pounds by 703.

  • Divide that answer by your height in inches.

  • Divide that answer by your height in inches again.

 

For example, a woman who weighs 270 pounds (122 kilograms) and is 68 inches (172 centimeters) tall has a BMI of 41.0. Use the chart to see what category your BMI falls into, and whether you need to be concerned about your weight.

 

Use the chart to see what category your BMI falls into

BMI is not always the best way to decide whether you need to lose weight. If you have more or less muscle than is normal, your BMI may not be a perfect measure of how much body fat you have:

  • Body builders. Because muscle weighs more than fat, people who are very muscular may have a high BMI.

  • Elderly. In older adults it is often better to have a BMI between 25 and 27, rather than under 25. If you are older than 65, for example, a slightly higher BMI may help protect you from thinning of the bones (osteoporosis).

  • Children. While many children are obese, DO NOT use this BMI calculator for evaluating a child. Talk to your child's provider about the right weight for your child's age.

 

Providers use a few methods to decide whether you are overweight. Your provider may also take your waist circumference and waist-to-hip ratio into consideration.

Your BMI alone can't predict your health risk, but most experts say that a BMI greater than 30 (obesity) is unhealthy. No matter what your BMI is, exercise can help reduce your risk of heart disease and diabetes. Remember to always talk to your provider before starting an exercise program.

 

NIH: National Institutes of Health

Prostate Specific Antigen (PSA)

Prostate-specific antigen (PSA) is a protein produced by prostate cells. The PSA test is done to help diagnose and follow prostate cancer in men.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

Make sure your health care provider knows all the medicines you are taking. Some drugs cause your PSA level to be falsely low. In most cases, no other special steps are needed to prepare for this test.

How the Test will Feel

You may feel slight pain or a prick when the needle is inserted. Afterward, there may be some throbbing or a slight bruise. These soon go away.

Why the Test is Performed

Reasons for a PSA test:

  • This test may be done to screen for prostate cancer.

  • It is also used to follow people after prostate cancer treatment to see if the cancer has come back.

  • If a provider feels the prostate gland is not normal during physical exam.

MORE ABOUT SCREENING FOR PROSTATE CANCER

Measuring the PSA level can increase the chance of finding prostate cancer when it is very early. But there is debate over the value of the PSA test for detecting prostate cancer. No single answer fits all men.

Before having the test, talk to your provider about the pros and cons of having a PSA test. Ask about:

  • Whether screening decreases your chance of dying from prostate cancer.

  • Whether there is any harm from prostate cancer screening, such as side-effects from testing or overtreatment of cancer when discovered.

If you choose to be tested, the PSA is most often done every year to screen men:

  • From ages 55 to 69, if no risk factors are present.

  • Starting around age 40 to 45 if they have a higher chance of developing prostate cancer. A family history of prostate cancer (especially a brother or father) and being African-American are more common risk factors.

 

NIH: National Institutes of Health

Sexually Transmitted Diseases Test (STD)

Sexually transmitted diseases (STDs) are infections that are passed from one person to another through sexual contact. The causes of STDs are bacteria, parasites, yeast, and viruses. There are more than 20 types of STDs, including

  • Chlamydia

  • Genital herpes

  • Gonorrhea

  • HIV/AIDS

  • HPV

  • Syphilis

  • Trichomoniasis

Most STDs affect both men and women, but in many cases the health problems they cause can be more severe for women. If a pregnant woman has an STD, it can cause serious health problems for the baby.

Antibiotics can treat STDs caused by bacteria, yeast, or parasites. There is no cure for STDs caused by a virus, but medicines can often help with the symptoms and keep the disease under control.

Correct usage of latex condoms greatly reduces, but does not completely eliminate, the risk of catching or spreading STDs.

 

Centers for Disease Control and Prevention

Pregnancy Test

A pregnancy test measures a hormone in the body called human chorionic gonadotropin (HCG). HCG is a hormone produced during pregnancy. It appears in the blood and urine of pregnant women as early as 10 days after conception.

How the Test is Performed

A pregnancy test is done using blood or urine. There are 2 types of blood tests:

  • Qualitative, which measures whether the HCG hormone is present

  • Quantitative, which measures how much HCG is present

The blood test is done by drawing a single tube of blood and sending it to a laboratory. You may wait anywhere from a few hours to more than a day to get the results.

The urine HCG test is most often performed by placing a drop of urine on a prepared chemical strip. It takes 1 to 2 minutes for a result.

For the urine test, you urinate into a cup.

For the blood test, the health care provider uses a needle and syringe to draw blood from your vein into a tube. Any discomfort you might feel from the blood draw will only last a few seconds.

How the Test will Feel

For the urine test, you urinate into a cup.

For the blood test, the health care provider uses a needle and syringe to draw blood from your vein into a tube. Any discomfort you might feel from the blood draw will only last a few seconds.

Why the Test is Performed

This test is done to:

  • Determine if you are pregnant

  • Diagnose abnormal conditions that can raise HCG levels

  • Watch the development of the pregnancy during the first 2 months (quantitative test only)

 

NIH: National Institutes of Health