Ultimate guide to decode your blood test report

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?

Regular blood testing is one of the most important ways to keep track of your overall physical well-being.

Getting tested at routine intervals can allow you to see the way your body changes over time and empower you to make informed decisions about your health.

How often should I get routine blood work?

Your doctor will typically recommend that you get routine blood work at least once a year, around the same time as your yearly physical.

But this is the bare minimum. There are several major reasons you may want to get blood tests more often than that:

  • You’re experiencing unusual, persistent symptoms. These could include anything from fatigue to abnormal weight gain to new pain.
  • You want to optimize your health. Knowing levels of various blood components, such as HDL and LDL cholesterol, can allow you to tweak your diet or fitness plan to minimize unhealthy habits (that you may not even realize are unhealthy). This can also maximize the nutrients you put in your body and more.
  • You want to reduce your risk of disease or complications. Regular blood tests can catch the warning signs of almost any disease early. Many heart, lung, and kidney conditions can be diagnosed using blood tests.

Talk to your doctor first if you want to get certain tests more often than once a year.

What are some routine tests and others I should ask about?

Some of the most common routine tests are:

  • complete blood count (CBC)
  • chemistry (basic metabolic) panel
  • thyroid panel
  • nutrient tests for levels of vital nutrients, such as iron or B vitamins

Some other tests that you may want include:

  • enzyme markers if you’re at risk for cancer or other conditions like liver cirrhosis, stroke, or celiac disease
  • sexually transmitted disease (STD) tests if you have multiple sexual partners or a new partner

Why do some blood tests require fasting?

Everything you eat and drink contains vitamins, proteins, and other nutrients that can cause the related levels in your blood to temporarily spike or drop.

Fasting for 8–12 hours helps ensure that blood test results are free from these variables, making your test results as accurate as possible.

Some common tests that may require fasting include:

  • cholesterol tests
  • blood sugar tests
  • liver function tests
  • kidney function tests
  • basic metabolic panel
  • glucose tests

How long does it take to get results?

Results may take anywhere from a few hours to a few days to become available. Here’s an overview of how long some common tests may take:

  • complete blood count (CBC): 24 hours
  • basic metabolic panel: 24 hours
  • complete metabolic panel: 24–72 hours
  • Lipid panel: 24 hours.

This can depend on the specific lab where you get tested or how many tests you get done at once. If you order multiple tests, you may not get the complete results until all of the tests are completed.

Sometimes a lab will only release results to your doctor, who reviews them and then releases them to you.

Who orders my blood tests?

Your doctor typically orders blood tests for you during a physical, checkup, or an appointment intended for a specific condition.

Blood testing is usually partially or fully covered by insurance. Ordering tests through your medical provider ensures that you’re not paying too much. Your doctor can also advise you on how to choose testing facilities that are reliable, well-managed, or convenient for you.

It’s possible to order your own blood tests without a doctor or even health insurance, but it’s not recommended. You may end up paying the full cost by not going through an insurance plan, which can be expensive.

Why blood work results matter

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. Trusted Source Normal ranges are established by testing a large group of healthy people.

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.

A blood test – sometimes referred to as a blood panel – is a laboratory examination of a blood sample used to check for a variety of things, including the functioning of certain organs (such as the liver, kidneys, thyroid and heart), infections and certain genetic disorders, as well as to assess an individual’s general health.

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.

Blood test abbreviations

Blood test results generally use the metric system of measurement and various abbreviations, including:

  • cmm: cells per cubic millimeter
  • fL (femtoliter): fraction of one-millionth of a liter
  • g/dL: grams per deciliter
  • IU/L: international units per liter
  • mEq/L: milliequivalent per liter
  • mg/dL: milligrams per deciliter
  • mL: milliliter
  • mmol/L: millimoles per liter
  • ng/mL: nanograms per milliliter
  • pg (picograms): one-trillionth of a gram

Blood testing is a huge topic. There are different types of blood test done for different purpose.

Blood samples are typically used to perform four different types of tests:

Hematology Tests: Used to measure the number and amount of “formed elements” in the blood. Formed elements include red blood cells, white blood cells, and platelets.


Blood chemistry Tests: Used to measure chemicals in the blood, such as those produced by the liver, as well as nutritional elements such as vitamins, proteins, fats, and sugar.


Microbiology Tests: Used to find certain disease-causing microorganisms in the blood. These can include bacteria, fungi, and parasites.


Serology Tests: Used to find antibodies produced by the immune system in response to specific disease-causing microorganisms. The HIV and hepatitis C virus (HCV) antibody tests are examples of serology tests.

Let us understand the tests one by one:

Blood test results components

A blood test is typically composed of three main tests: a complete blood count, a metabolic panel and a lipid panel. Each test for different things, which can be understood through a detailed analysis of the results.

Confusingly, it is likely that the results of the three tests will not be differentiated from each other and, instead, will be listed under one large column, often labelled “Test Name”. Within each are various sub-tests, which altogether give a broad picture of an individual’s health.

Complete blood count (CBC)

The complete blood count (CBC) concentrates on the three types of blood cells: white blood cells (WBCs), red blood cells (RBCs) and platelets. By measuring the volume of blood cells, the CBC allows a doctor to evaluate an individual’s overall health, as well as check for underlying conditions such as leukemia and anemia.

The subtests within the CBC are:

White blood cell (WBC) count

Also known as leukocytes, white blood cells are a major component of the body’s immune system. A high white blood cell count can indicate the presence of infection, while a low count can point towards various conditions, including HIV/AIDS and lupus.

Differential white blood cell count

The lab tests the five main components of white blood cells and their proportion to each other. If the components are out of balance, this could indicate an infection, as well as a variety of medical conditions. Healthy proportions for each are:

  • Neutrophils: 40 to 60 percent of the total
  • Lymphocytes: 20 to 40 percent
  • Monocytes: 2 to 8 percent
  • Eosinophil’s: 1 to 4 percent
  • Basophils: 0.5 to 1 percent

Red blood cell (RBC) count

Red blood cells (RBCs) carry oxygen to tissues throughout the body, making them important to its healthy functioning. A red blood cell count estimates the volume of RBCs within an individual – if the results show a count above or below normal levels this can indicate various medical conditions to a doctor. However, this form of testing is unable to pinpoint the root causes of any irregularities, meaning, if this is the case, and further tests will be necessary.

Hematocrit (Hct) test

Tests what proportion of the blood is made up of RBCs? It is useful in diagnosing anemia, among other medical conditions.

Hemoglobin (Hgb) test

Hemoglobin is a protein contained within red RBCs that sends oxygen from the lungs to the body’s tissues. The hemoglobin test is also useful in diagnosing anemia, with many practitioners preferring this test over the hematocrit test.7

Mean corpuscular volume (MCV) test

The average volume of RBCs, or the space each red blood cell fills, is measured through this test. Results outside of the normal range can be a sign of anemia or chronic fatigue syndrome, among other medical conditions.

Mean corpuscular hemoglobin (MCH) test

The lab tests the average amount of hemoglobin present in each red blood cell. High levels are a possible indicator of anemia and low levels a possible sign of malnutrition.

Red cell distribution width (RDW or RCDW) test

Tests the distribution of RBCs, not their actual size. Levels outside of the normal range can indicate conditions such as anemia, malnutrition and liver disease.

Platelet count

Platelets are small cells that help the blood to clot. This test measures the amount of platelets present in the blood. If testing highlights a high count, this can indicate anemia, cancer or infection, while a low count can prevent wounds from healing and result in severe bleeding.

Mean platelet volume (MPV)

Tests the volume of platelets in the blood. A low platelet volume can cause irregularities with bleeding, while a high platelet volume can increase an individual’s risk of heart attack or stroke.

Comprehensive metabolic panel (CMP)

The comprehensive metabolic panel test, also known as a chemistry panel, measures the body’s glucose levels, fluid and electrolyte balance, as well as liver and kidney function. It consists of a number of sub-tests:

Alanine aminotransferase (ALT) test

Alanine aminotransferase (ALT) is an enzyme mostly produced by liver cells. High levels can be an indication of liver damage.

Albumin test

Albumin is a protein produced by the liver. Its volume within the organ can be measured via this test. Abnormal levels can be caused by liver or kidney problems.

Total protein test

The lab tests the ratio of two types of proteins: albumin and globulin. Low protein levels can indicate various conditions, including liver and kidney disorders and malnutrition, while high levels can be a sign of inflammation, infection or bone marrow disorder.

Alkaline phosphatase test

Alkaline phosphatase is an enzyme typically produced in liver and bone cells. Results outside of the normal levels can signal liver damage and bone problems such as rickets or bone tumors.

Aspartate aminotransferase test

Aspartate aminotransferase is an enzyme usually found in RBCs and muscle tissue, as well as the heart, pancreas, liver and kidneys. This test measures the levels of this enzyme in the body, with results above the healthy range indicating a variety of conditions, including some types of cancer, as well as liver, heart or kidney damage.

Bilirubin test

The lab tests for kidney and liver dysfunction which is useful in diagnosing conditions such as neonatal jaundiceanemia and liver diseases.

Blood urea nitrogen (BUN) test

This test measures the volume of nitrogen in the blood. High levels can be caused by kidney damage or disease, while low levels may be a sign of malnutrition or severe liver damage.

Calcium test

This test measures the levels of calcium in the blood. If testing indicates low levels, this can indicate cancer, hyperparathyroidism, tuberculosis and other conditions, while high levels can indicate conditions including malnutrition, rickets and hyperparathyroidism.

Chloride test

This test measures the body’s chloride levels. An increased level of chloride can indicate dehydration as well as kidney disorders and adrenal gland dysfunction.

Creatinine test

Creatinine is a chemical waste molecule that is important for creating muscle energy. Increased levels of creatinine can be a sign of kidney dysfunction.

Fasting blood sugar test

Blood sugar levels are easily affected by recent food or drink intake. The fasting blood sugar test is therefore done after a minimum of six hours of fasting. Abnormal results can indicate diabetes, among other medical conditions.

Phosphorus test

The lab tests the amount of phosphorus in the blood. Elevated levels can indicate problems with the kidneys and parathyroid glands, and they may be a sign of malnutrition or alcohol abuse.

Potassium test

Potassium aids the communication between nerves and muscles, regulates the heart and maintains muscle function. Diuretics (a substance or medication used to increase urination) can cause potassium levels to fall.

Sodium test

Sodium is a mineral that aids nerve impulses and muscle contractions, as well as balancing water levels. Irregularities are a possible indication of dehydration, adrenal gland disorders, corticosteroids, and kidney or liver disorders.

Lipid panel

The lipid panel consists of various tests used to measure the different types of triglycerides (fats) and cholesterol in the blood.

Total cholesterol test

This test measures the overall levels of LDL (bad) and HDL (good) cholesterol in the blood.

Triglycerides test

Tests for triglycerides, a fat found in the blood. Irregularities are a possible risk factor for heart disease and other medical conditions.

HDL cholesterol test

HDL cholesterol, also known as high-density lipoprotein (or good cholesterol), is useful in protecting against heart disease. Low levels can increase the risk of heart problems.

LDL cholesterol test

LDL cholesterol, also known as low-density lipoprotein (or bad cholesterol), is linked to heart disease and clogged arteries.

Total cholesterol to HDL ratio test

Calculating this ratio can help determine an individual’s risk of developing a heart disease. It is worked out by dividing HDL cholesterol into total cholesterol. High levels are a possible indicator of heart problems.

Causes for Abnormal Values:


  • Due to Cigarette Smoking
  • Congenital heart Disease
  • Dehydration
  • Renal Cell carcinoma (A type of Kidney cancer)
  • Pulmonary Fibrosis (A condition that causes lung scarring and stiffness)
  • Polycythemia Vera (A bone marrow disease that causes overproduction of RBCs and is associated with a genetic mutation


  • AnimeaBone marrow failure
  • Erythropoietin deficiency (The primary cause of anemia in patients with chronic kidney disease)
  • Hemolysis (RBC destruction caused by transfusions and blood vessel injury)
  • Internal or external bleeding
  • Leukemia
  • Malnutrition
  • Multiple myeloma (A cancer of the plasma cells in bone marrow)
  • Nutritional deficiencies, including deficiencies in iron, copper, folate, and vitamins B-6 and B-12
  • Pregnancy
  • Thyroid disorders
  • Certain drugs can also lower your RBC count.


Men: 38.8 to 50 percent
Women: 34.9 to 44.5 percent
Children: Kids aged 15 and under have a separate set of ranges, as their Hematocrit levels change rapidly with age.

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Congenital heart disease
  • Dehydration
  • Kidney tumor
  • Lung diseases
  • Polycythemia ver


  • Bone marrow diseases
  • Chronic inflammatory disease
  • Deficiencies in nutrients such as iron, folate, or vitamin B-12
  • Internal bleeding
  • Hemolytic anemia
  • Kidney failure
  • Leukemia
  • Lymphoma
  • Sickle cell anemia


Men: 11-18g/dL
Women: 12-16g/dL
Pregnant Women: 11-16g/dL
Infant: 11-18g/dL
Young Children:11.516.5g/dL

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Living at high altitudes where there’s not as much oxygen
  • Smoking
  • Chronic obstructive pulmonary disease (COPD) (A condition that inflames the lungs and blocks air from getting into your lungs)
  • Heart or lung diseases
  • Other reasons Includes:
  • Being severely dehydrated
  • Heart failure
  • Cancer of the liver or kidneys


  • Lack of iron in your diet
  • Lack of folate or vitamin B-12
  • Severe blood loss after surgery or a major injury
  • Internal bleeding from stomach ulcers, stomach or colon cancer, or internal injuries
  • Sickle cell anemia
  • Hypothyroidism
  • Splenomegaly (A condition that occurs when your spleen becomes enlarged)
  • Bone marrow conditions, such as leukemia (prevent your bone marrow from producing enough red blood cells)
  • Chronic kidney disease

Mean corpuscular hemoglobin (MCH)

27.5 and 33.2 pictograms (pg)

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


Caused by anemia due to a deficiency of B vitamins, particularly B-12 and folate.


Caused by iron deficiency

Mean corpuscular hemoglobin concentration (MCHC)


Actual Value (These ranges may vary depending on the laboratory or doctor)

This measures the concentration of hemoglobin in a certain amount of blood. It is calculated by dividing the Hgb by Hct.

Mean Corpuscular Volume (MCV)

80 and 96 hectoliters per cell.

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


Vitamin B12 deficiency and Anemia


Iron Deficiency and Anemia.

Red cell distribution width (RDW)

Men: 11.8 to 14.5 percent
Women: 12.2 to 16.1 percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


An indication of a nutrient deficiency, such as a deficiency of iron, folate, or vitamin B-12.


There are no Hematologic disorders associated with a low RDW result.


150,000 to 450,000 platelets per micro liter of blood

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:



  • Infection
  • Inflammatory states (for example, inflammatory bowel disease)
  • Physical stress (including the post- operative state)
  • Acute blood loss
  • Iron deficiency anemia



  • Vitamin B-12 deficiency.
  • Folate deficiency.
  • Iron deficiency.
  • Viral infections, including HIV, Epstein-Barr, and chickenpox.
  • Exposure to chemotherapy, radiation, or toxic chemicals.
  • Consuming too much alcohol.
  • (Condition in which the liver does not function properly due to long-term damage.)

White Blood Cells (WBC)

New Born: 9,000 to 30,000
Children Under age 2: 6,200 to 17,000
Children from age 2 to Adults: 5,000 to 10,000

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


Can have Causes that aren’t due to Underlying Disease.


Caused By Viral Infection.

The normal percentages of the types of WBC’s in your overall count are usually in these ranges.


55 to 73 percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Neutrophilia (A white blood cell disorder that can be caused by an infection, steroids, smoking, or rigorous exercise)
  • An acute infection, especially a bacterial infection
  • Acute stress
  • Pregnancy
  • Inflammation, such as inflammatory bowel disease or rheumatoid arthritis.
  • Tissue injury due to trauma.
  • Chronic leukemia


  • Neutropenia (A white blood cell disorder that can be caused by a lack of neutrophil production in the bone marrow).
  • Aplastic anemia (A decrease in the number of blood cells produced by your bone marrow).
  • A severe or widespread bacterial or viral infection.
  • Recent chemotherapy or radiation therapy treatments


20 to 40 Percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Lymphoma (A white blood cell cancer that starts in your lymph nodes)
  • A chronic bacterial infection
  • Hepatitis
  • Multiple myeloma (A cancer of the cells in your bone marrow)
  • A viral infection, such as mononucleosis, mumps, or measles
  • Lymphocytic leukemia


  • Bone marrow damage due to chemotherapy or radiation treatments
  • HIV, tuberculosis, or hepatitis infection
  • Leukemia
  • A severe infection, such as sepsis
  • An autoimmune disorder, such as lupus or rheumatoid arthritis


1 to 4 Percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Eosinophilia, which can be caused by allergic disorders, parasites, tumors, or gastrointestinal (GI) disorders.
  • An allergic reaction.
  • Skin inflammation, such as eczema or dermatitis.
  • A parasitic infection
  • An inflammatory disorder, such as inflammatory bowel disease or celiac disease
  • Certain cancers


  • Intoxication from alcohol or excessive production of cortisol, like in Cushing’s disease. Cortisol is a hormone naturally produced by the body. Low eosinophil counts may also be due to the time of day.
  • Not a concern unless other WBC are normal


2 to 8 Percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • Chronic inflammatory disease, such as inflammatory bowel disease
  • A parasitic or viral infection
  • A bacterial infection in your heart
  • A collagen vascular disease, such as lupus, vasculitis, or rheumatoid arthritis
  • Certain types of leukemia


  • Chemotherapy and radiation therapy, which can injure bone marrow.
  • HIV and AIDS, which
  • Weaken the body’s immune system.
  • Sepsis (an infection of the bloodstream).


0.5 to 1 percent

Actual Value (These ranges may vary depending on the laboratory or doctor)

Causes for Abnormal Values:


  • A serious food allergy
  • Inflammation
  • Leukemia


  • May be due to a severe allergic reaction. If you develop an infection, it may take longer to heal.

Bottom line

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.



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Science Blogger

I’m a life long learner who loves reading, painting, sci-fi and travelling. As the publisher of The Sciencelock, I edits the website Features and writes articles across the publication.

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