Even if you’re a CrossFit champ or a marathon maven, getting a regular checkup just makes sense. What doesn’t always make sense is the baffling list of medical terms on the blood test results that are often part of routine exams.
Navigating through these terms can lead you down a Google rabbit hole. What the heck is bilirubin? And if you’re all about that bass, could your heart be pumping too many basophils?
Apart from the puzzling jargon, the design of bloodwork lab reports is dismal. We’re stuck deciphering highly technical and administrative-looking documents that make tax forms look like an e-card from mom.
But have no fear: You can become literate in your blood test results.
Our guide isn’t a comprehensive glossary of technical terms, but it’ll give you basic definitions and a better sense of how the information on a typical blood test report is presented and organized, so you can interpret your blood work with more confidence.
First, let’s talk about why your blood work results are so important. It’s helpful to think of your blood as both an oxygen delivery system and a waste removal mechanism.
Certain organs in your body, such as your liver, kidneys, spleen, and lungs, act as processing stations. Normal values on a lab report indicate healthy organ function and fully operational systems.
It’s important to note that out-of-range test values aren’t necessarily a sign of imminent disease.
But those ranges can be influenced by a variety of factors for each person, including age, sex, weight, medical history, medicines, and lifestyle. What’s “normal” for you is best determined by your doctor.
For a routine checkup, a blood sample is usually examined with three main tests:
- a complete blood count (CBC)
- a comprehensive metabolic panel (CMP)
- a lipid panel (or profile)
These tests return a number of specific results. However, instead of grouping the results under each of the three tests, many reports simply present a single column of test results under “Test Name.”
To better understand your lab report, it’s helpful to recognize the relationship of the test results. Here are basic descriptions of the three major tests and the results that are most commonly listed under each.
In many blood test results, the first list under the “Test Name” column shows the results of the CBC, or complete blood count. The CBC measures the essential components of blood: red blood cells, white blood cells, and platelets.
The CBC also measures the oxygen-carrying protein, hemoglobin, and checks the ratio of red blood cells to fluid (plasma).
Blood test results help your doctor identify infections and allergies or diagnose potential diseases and conditions such as anemia and leukemia.
White blood cell (WBC) count
Often the first CBC test shown is the white blood cell count. White blood cells, also called leukocytes, are a major component of your body’s immune system.
Your body produces more WBCs when you have an infection or allergic reaction. There are five major types of WBCs (covered below), but many blood test result reports list each of these at the bottom of the CBC results.
WBC count might also offer clues about your heart health. A 2018 study found that a high WBC count was a predictor of heart disease, and particularly stroke, especially among smokers.
Red blood cell (RBC) count
Red blood cells often appear next on the report. RBCs deliver oxygen to tissues throughout your body.
High RBC counts can be the result of dehydration, kidney problems, or a heart condition. Low RBC counts can indicate anemia, nutritional deficiencies, bone marrow damage, or kidney problems.
A high RBC could also signal fatty liver disease, a condition in which fat builds up in and damages your liver. It could be a warning to people with obesity, type 2 diabetes, and high cholesterol, since those conditions have been linked to fatty liver disease.
Hemoglobin, hematocrit, and more
These test results often appear under the RBC section because they further examine the health and function of your red blood cells.
Hemoglobin is the protein in red blood cells that carries oxygen. Its measurement can help your doctor tell if your organs and tissues are getting enough oxygen.
Hematocrit results show the volume of blood taken up by red blood cells. Low hematocrit can be a sign of anemia, blood loss, or a vitamin deficiency. A spike could be from dehydration or liver or heart disease.
Blood cells are often referred to as corpuscles. The mean corpuscular value measures the average size of red blood cells. A vitamin B-12 deficiency or anemia could lead to abnormal-size RBCs.
Mean corpuscular hemoglobin measures the average amount of hemoglobin in RBCs. It’s often evaluated along with the mean corpuscular hemoglobin concentration (MCHC), which measures the average percentage of hemoglobin in RBCs.
Platelets and mean platelet value (MPV)
These two tests usually appear next. Platelets are fragments of blood cells. They help wounds heal and prevent excessive bleeding by forming clots.
A low platelet count — below 150,000 platelets per microliter (mcL) — can indicate risk for excessive bleeding, while a high count (400,000 or above) may indicate a risk for blood clots.
The mean platelet value test measures the average amount of platelets. It can help diagnose bleeding and bone marrow disorders and offer clues to inflammatory diseases, including cardiovascular disease, lupus, and rheumatoid arthritis.
Types of white blood cells
Oddly, the results for the five types of white blood cells — basophils, eosinophils, neutrophils, lymphocytes, and monocytes — often appear below the list of red blood cell results.
Measuring the amounts and health of these cells is helpful in identifying infections and allergies.
For example, neutrophils are like the EMTs of your blood. They’re immune cells that are among the first to arrive at the site of an infection. Basophils, another type of immune cell, have small particles with enzymes that are released during allergic reactions and asthma.
The word “metabolism” in this part of your blood work results may bring to mind the number on the scale (and maybe dozens of diet books with the words “mega” and “blast” shouting in all caps).
In reality, this group of tests provides a much broader picture of your body’s chemical balance and metabolism.
To clarify, “metabolism” refers to all the physical and chemical processes in your body that convert or use energy (breathing, controlling body temperature, etc.).
The CMP provides information about electrolytes, minerals in your blood that affect the amount of water in your body, the acidity of your blood, and your muscle function.
Common electrolytes the CMP tests for include calcium, chloride, magnesium, phosphorous, potassium, and sodium.
Bilirubin, albumin, and creatinine
In addition, the CMP often measures substances such as bilirubin, albumin, and creatinine.
Bilirubin forms when your body breaks down hemoglobin. It’s found in bile and blood, and too much of it could indicate jaundice.
Albumin, the main protein in blood plasma, is the clear, yellowish fluid part of the blood that carries blood cells. Low levels of albumin can indicate malnutrition, inflammation, and liver and kidney diseases.
Creatinine is a chemical waste product of creatine, which supplies energy to muscles. Since it can help you crush your weightlifting goals, creatine is a popular supplement. But because your kidneys remove creatinine, elevated levels could signal poor kidney function.
Fasting glucose test
Another part of the CMP is often the fasting glucose test, which requires that you don’t eat for at least 8 hours beforehand. Glucose is your body’s main source of energy. Abnormal glucose levels can be a sign of diabetes.
Glucose is a simple sugar your body manufactures from carbohydrates, so that stack o’ pancakes could affect the test’s outcome.
Tip: Schedule your blood work for first thing in the morning, if possible, to avoid “the hangries,” which are a legit problem.
At Greatist, we’re not cool with body-negative “fat talk.” But talking about your lipids (aka the fat in the body) in your blood work is totally fair game.
Just like the fat on your plate, it’s not all bad. Your body breaks down lipids and uses them for energy. The lipid panel is a collection of tests that measures two types of fat in your blood: triglycerides and cholesterol.
Triglycerides are one of the major forms of fat produced in your liver. If you’re wondering what affects your triglyceride levels, line up the usual dietary suspects: sugar, fat, and alcohol.
But triglyceride levels can also be high because of thyroid or liver disease or genetic conditions.
There are two types of cholesterol: HDL and LDL.
HDL stands for “high-density lipoprotein.” It’s a fat that takes extra cholesterol from your blood to your liver for removal. It’s often called the “good” cholesterol, because high levels of it are desirable and linked to a lower risk of cardiovascular disease.
LDL stands for “low-density lipoprotein.” It’s a fat that transports cholesterol to parts of your body in need of cell repair. But it can also build up on the inside of arteries, so it’s often called the “bad” cholesterol.
High levels of LDL cholesterol are linked to an increased risk of heart and blood vessel disease, including coronary artery disease.
Maintaining a healthy number of triglycerides and the right balance of good and bad cholesterol is essential for a heart-healthy lifestyle.
High triglyceride levels are also linked to a higher risk of heart and blood vessel disease. And research shows that LDL cholesterol isn’t the only bad guy when it comes to heart disease risk: The ratio of triglycerides to HDL cholesterol can be problematic too.
Often your blood work results are sent to you in the mail. Unless your doctor is concerned about particular results that fall out of range, the report will likely be accompanied by a letter that basically says, “Well done — keep up the good work!”
Sure, you can accept this at face value. But being an informed patient is an important part of developing a strong doctor-patient relationship.
With your newly acquired understanding of the terms and objectives of your blood test, you can become a more active participant in your healthcare and a better custodian of your body.