10 Most Important Tests

Immature forms of neutrophils are called neutrophilic band cells. Neutrophils are a type of white blood cell that is responsible for much of the body's protection against infection. Neutrophils are produced in the bone marrow and released into the bloodstream to travel to wherever they are needed. Large numbers of immature forms of neutrophils, called neutrophilic band cells, are produced by the bone marrow when the demand is high.

Basophils normally constitute 1% or less of the total white blood cell count but may increase or decrease in certain diseases and are thought to be involved in allergic reactions.

Blasts are immature forms of white blood cells.

Eosinophils (eos) respond to infections caused by parasites and play a role in allergic reactions (hypersensitivities)

Lymphocytes are white blood cells that exist in both the blood and the lymphatic system. They are divided into three types. The B lymphocytes (B cells) are antibody-producing cells that are essential for acquired, antigen-specific immune responses. The second type are T lymphocytes (T cells) some T cells help the body distinguish between "self" and "non-self" antigens while others initiate and control the extent of an immune response, boosting it as needed and then slowing it as the condition resolves. Other types of T cells directly attack and neutralize virus-infected or cancerous cells. The third type are natural killer cells (NK cells) that directly attack and kill abnormal cells such as cancer cells or those infected with a virus.

Metamyelocytes are immature forms of white blood cells.

Monocytes (mono), similar to neutrophils, move to an area of infection and engulf and destroy bacteria. They are associated more often with chronic rather than acute infections. They are also involved in tissue repair and other functions involving the immune system.

Myelocytes are immature forms of white blood cells.

Neutrophils (neu) normally make up the largest number of circulating WBCs. They move into an area of damaged or infected tissue, where they engulf and destroy bacteria or sometimes fungi. Young neutrophils, recently released into circulation, are called bands.

Nucleated Red Blood Cells (nRBC) ) the presence of NRBCs in the adult blood is usually associated with malignant neoplasms, bone marrow diseases, and other serious disorders.

Promyelocytes are immature forms of white blood cells.

Immature forms of neutrophils are called neutrophilic band cells. Neutrophils are a type of white blood cell that is responsible for much of the body's protection against infection. Neutrophils are produced in the bone marrow and released into the bloodstream to travel to wherever they are needed. Large numbers of immature forms of neutrophils, called neutrophilic band cells, are produced by the bone marrow when the demand is high.

Basophils normally constitute 1% or less of the total white blood cell count but may increase or decrease in certain diseases and are thought to be involved in allergic reactions.

Blasts are immature forms of white blood cells.

Eosinophils (eos) respond to infections caused by parasites and play a role in allergic reactions (hypersensitivities)

Hematocrit is a blood test that measures the percentage of the volume of whole blood that is made up of red blood cells. This measurement depends on the number of red blood cells and the size of red blood cells.

Serum hemoglobin is a blood test that measures the level of free hemoglobin in the liquid part of the blood (the serum). Free hemoglobin is the hemoglobin outside of the red blood cells. Most of the hemoglobin is found inside the red blood cells, not in the serum.

Lymphocytes are white blood cells that exist in both the blood and the lymphatic system. They are divided into three types. The B lymphocytes (B cells) are antibody-producing cells that are essential for acquired, antigen-specific immune responses. The second type are T lymphocytes (T cells) some T cells help the body distinguish between "self" and "non-self" antigens while others initiate and control the extent of an immune response, boosting it as needed and then slowing it as the condition resolves. Other types of T cells directly attack and neutralize virus-infected or cancerous cells. The third type are natural killer cells (NK cells) that directly attack and kill abnormal cells such as cancer cells or those infected with a virus.

Mean corpuscular hemoglobin (MCH) is a calculation of the average amount of oxygen-carrying hemoglobin inside a red blood cell.

Mean corpuscular hemoglobin concentration (MCHC) is a calculation of the average percentage of hemoglobin inside a red cell.

Mean corpuscular volume (MCV) is a measurement of the average size of RBCs.

Metamyelocytes are immature forms of white blood cells.

Monocytes (mono), similar to neutrophils, move to an area of infection and engulf and destroy bacteria. They are associated more often with chronic rather than acute infections. They are also involved in tissue repair and other functions involving the immune system.

Mean Platelet Volume (MPV) - When it indicates average size of platelets are small; older platelets are generally smaller than younger ones and a low MPV may mean that a condition is affecting the production of platelets by the bone marrow. When it indicates a high number of larger, younger platelets in the blood; this may be due to the bone marrow producing and releasing platelets rapidly into circulation.

Myelocytes are immature forms of white blood cells.

Neutrophils are a type of white blood cell that is responsible for much of the body's protection against infection. Neutrophils are produced in the bone marrow and released into the bloodstream to travel to wherever they are needed.

Nucleated Red Blood Cells (nRBC) ) the presence of NRBCs in the adult blood is usually associated with malignant neoplasms, bone marrow diseases, and other serious disorders.

A platelet count is a test to measure how many platelets you have in your blood. Platelets help the blood clot. They are smaller than red or white blood cells.

Promyelocytes are immature forms of white blood cells.

Red cell distribution width (RDW), which may be included in a CBC, is a calculation of the variation in the size of RBCs.

Lymphocytes are white blood cells that exist in both the blood and the lymphatic system. They are divided into three types. The B lymphocytes (B cells) are antibody-producing cells that are essential for acquired, antigen-specific immune responses. The second type are T lymphocytes (T cells) some T cells help the body distinguish between "self" and "non-self" antigens while others initiate and control the extent of an immune response, boosting it as needed and then slowing it as the condition resolves. Other types of T cells directly attack and neutralize virus-infected or cancerous cells. The third type are natural killer cells (NK cells) that directly attack and kill abnormal cells such as cancer cells or those infected with a virus.

An RBC count is a blood test that tells how many red blood cells (RBCs) you have. RBCs contain hemoglobin, which carries oxygen. How much oxygen your body tissues get depends on how many RBCs you have and how well they work.

A WBC count is a test to measure the number of white blood cells (WBCs) in the blood. WBCs help fight infections. They are also called leukocytes. There are five major types of white blood cells: basophils, eosinophils, lymphocytes (T cells and B cells), monocytes and neutrophils

Albumin is a protein made by the liver. A serum albumin test measures the amount of this protein in the clear liquid portion of the blood.

The ratio of albumin to globulin (A/G ratio) is calculated from measured albumin and calculated globulin (total protein - albumin). Normally, there is a little more albumin than globulins, giving a normal A/G ratio of slightly over 1. Because disease states affect the relative amounts of albumin and globulin, the A/G ratio may provide a clue as to the cause of the change in protein levels. A low A/G ratio may reflect overproduction of globulins, such as seen in multiple myeloma or autoimmune diseases, or underproduction of albumin, such as may occur with cirrhosis, or selective loss of albumin from the circulation, as may occur with kidney disease (nephrotic syndrome). A high A/G ratio suggests underproduction of immunoglobulins as may be seen in some genetic deficiencies and in some leukemias. More specific tests, such as liver enzyme tests and serum protein electrophoresis, must be performed to make an accurate diagnosis. With a low total protein that is due to plasma expansion (dilution of the blood), the A/G ratio will typically be normal because both albumin and globulin will be diluted to the same extent.

Alkaline phosphatase (ALP) is a protein found in all body tissues. Tissues with higher amounts of ALP include the liver, bile ducts, and bone.

Alanine transaminase (ALT) is an enzyme found in the highest amounts in the liver. Injury to the liver results in release of the substance into the blood.

AST (aspartate aminotransferase) is an enzyme found in high amounts in liver, heart, and muscle cells. It is also found in lesser amounts in other tissues.

Bilirubin is a yellowish pigment found in bile, a fluid made by the liver. A small amount of older red blood cells are replaced by new blood cells every day. Bilirubin is left after these older blood cells are removed. The liver helps break down bilirubin so that it can be removed from the body in the stool.

A ratio between a person’s BUN and blood creatinine to help determine what is causing these concentrations to be higher than normal. The ratio of BUN to creatinine is usually between 10:1 and 20:1. An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys, such as congestive heart failure or dehydration. It may also be seen with increased protein, from gastrointestinal bleeding, or increased protein in the diet. The ratio may be decreased with liver disease (due to decrease in the formation of urea) and malnutrition.

You have more calcium in your body than any other mineral. Calcium has many important jobs. The body stores more than 99 percent of its calcium in the bones and teeth to help make and keep them strong. The rest is throughout the body in blood, muscle and the fluid between cells. Your body needs calcium to help muscles and blood vessels contract and expand, to secrete hormones and enzymes and to send messages through the nervous system.

CO2 is carbon dioxide. Measures the amount of carbon dioxide in the liquid part of your blood, called the serum. In the body, most of the CO2 is in the form of a substance called bicarbonate (HCO3-). Therefore, the CO2 blood test is really a measure of your blood bicarbonate level.

Chloride is a type of electrolyte. It works with other electrolytes such as potassium, sodium, and carbon dioxide (CO2). These substances help keep the proper balance of body fluids and maintain the body's acid-base balance. This is a measure of the amount of chloride in the fluid portion (serum) of the blood.

The creatinine blood test measures the level of creatinine in the blood. This test is done to see how well your kidneys work.

Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.

Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.

Globulins is the collective term for most blood proteins other than albumin. Identifying the types of globulins can help diagnose certain disorders. Globulins are roughly divided into three groups: alpha, beta, and gamma globulins. Gamma globulines include various types of antibodies such as immunoglobulins (Ig) M, G, and A.

A blood glucose test measures the amount of a sugar called glucose in a sample of your blood. Glucose is a major source of energy for most cells of the body, including those in the brain. The hormones insulin and glucagon help control blood glucose levels.

Potassium is a mineral that the body needs to work normally. It helps nerves and muscles communicate. It also helps move nutrients into cells and waste products out of cells. A diet rich in potassium helps to offset some of sodium's harmful effects on blood pressure.

The total protein is the total amount of two classes of proteins, albumin and globulin that are found in the fluid portion of your blood. Proteins are important parts of all cells and tissues. Your albumin helps prevent fluid from leaking out of blood vessels and your globulins are an important part of your immune system.

Sodium is a substance that the body needs to work properly it is vital to normal body processes, including nerve and muscle function

BUN stands for blood urea nitrogen. Urea nitrogen is what forms when protein breaks down. BUN measures the amount of urea nitrogen in the blood.

DHEA-sulfate test measures the amount of DHEA-sulfate in the blood. DHEA-sulfate is a weak male hormone (androgen) produced by the adrenal gland in both men and women.

Estradiol (estradiol-17 beta, E2) is part of an estrogen that is a group of steroids that regulate the menstrual cycle and function as the main female sex hormones. Estrogens are responsible for the development of female sex organs and secondary sex characteristics and are tied to the menstrual cycle and pregnancy. They are considered the main sex hormones in women and are present in small quantities in men. Estradiol (E2) is the predominant form of estrogen and is produced primarily in the ovaries with additional amounts produced by the adrenal glands in women and in the testes and adrenal glands in men. Estradiol levels are used in evaluating ovarian function. Estradiol levels are increased in cases of early (precocious) puberty in girls and gynecomastia in men. Its main use has been in the differential diagnosis of amenorrhea – for example, to determine whether the cause is menopause, pregnancy, or a medical problem. In assisted reproductive technology (ART), serial measurements are used to monitor follicle development in the ovary in the days prior to in vitro fertilization. Estradiol is also sometimes used to monitor menopausal hormone replacement therapy.

Ferritin is a protein found inside cells that stores iron so your body can use it later. A ferritin test indirectly measures the amount of iron in your blood. The amount of ferritin in your blood (serum ferritin level) is directly related to the amount of iron stored in your body.

Gamma-glutamyl transpeptidase (GGT) is a test to measure the amount of the enzyme GGT in the blood.

The A1c test evaluates the average amount of glucose in the blood over the last 2 to 3 months. It does this by measuring the concentration of glycated (also often called glycosylated) hemoglobin A1c. Hemoglobin is an oxygen-transporting protein found inside red blood cells (RBCs). There are several types of normal hemoglobin, but the predominant form – about 95-98% – is hemoglobin A. As glucose circulates in the blood, some of it spontaneously binds to hemoglobin A. The hemoglobin molecules with attached glucose are called glycated hemoglobin. The higher the concentration of glucose in the blood, the more glycated hemoglobin is formed. Once the glucose binds to the hemoglobin, it remains there for the life of the red blood cell – normally about 120 days. The predominant form of glycated hemoglobin is referred to as HbA1c or A1c. A1c is produced on a daily basis and slowly cleared from the blood as older RBCs die and younger RBCs (with non-glycated hemoglobin) take their place. This test is used to monitor treatment in someone who has been diagnosed with diabetes. It helps to evaluate how well their glucose levels have been controlled by treatment over time. This test may be used to screen for and diagnose diabetes or risk of developing diabetes. In 2010, clinical practice guidelines from the American Diabetes Association (ADA) stated that A1c may be added to fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) as an option for diabetes screening and diagnosis. For monitoring purposes, an A1c of less than 7% indicates good glucose control and a lower risk of diabetic complications for the majority of diabetics. However, in 2012, the ADA and the European Association for the Study of Diabetes (EASD) issued a position statement recommending that the management of glucose control in type 2 diabetes be more "patient-centered." Data from recent studies have shown that low blood sugar (hypoglycemia) can cause complications and that people with risk of severe hypoglycemia, underlying health conditions, complications, and a limited life expectancy do not necessarily benefit from having a stringent goal of less than 7% for their A1c. The statement recommends that people work closely with their doctor to select a goal that reflects each person's individual health status and that balances risks and benefits.

A high-sensitivity CRP (hs-CRP) test may be used by itself, in combination with other cardiac risk markers, or in combination with a lipoprotein-associated phospholipase A2 (Lp-PLA2) test that evaluates vascular inflammation. The hs-CRP test accurately detects low concentrations of C-reactive protein to help predict a healthy person's risk of cardiovascular disease (CVD). High-sensitivity CRP is promoted by some as a test for determining a person's risk level for CVD, heart attacks, and strokes. The current thinking is that hs-CRP can play a role in the evaluation process before a person develops one of these health problems.

Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries oxygen from our lungs throughout our bodies. It helps our muscles store and use oxygen. Iron is also part of many other proteins and enzymes. Your body needs the right amount of iron. If you have too little iron, you may develop iron deficiency anemia. Causes of low iron levels include blood loss, poor diet, or an inability to absorb enough iron from foods. People at higher risk of having too little iron are young children and women who are pregnant or have periods.

LDH isoenzymes is a test to check how much of the different types of lactate dehydrogenase (LDH) are in the blood. Measurement of LDH isoenzymes helps determine the location of any tissue damage. LDH is found in many body tissues such as the heart, liver, kidney, skeletal muscle, brain, blood cells, and lungs. LDH exists in 5 forms, which differ slightly in structure. LDH-1 is found primarily in heart muscle and red blood cells. LDH-2 is concentrated in white blood cells. LDH-3 is highest in the lung. LDH-4 is highest in the kidney, placenta, and pancreas. LDH-5 is highest in the liver and skeletal muscle.

Cholesterol is a waxy, fat-like substance that occurs naturally in all parts of the body. Your body needs some cholesterol to work properly. But if you have too much in your blood, it can combine with other substances in the blood and stick to the walls of your arteries. This is called plaque. Plaque can narrow your arteries or even block them. High levels of cholesterol in the blood can increase your risk of heart disease. Your cholesterol levels tend to rise as you get older. There are usually no signs or symptoms that you have high blood cholesterol, but it can be detected with a blood test. You are likely to have high cholesterol if members of your family have it, if you are overweight or if you eat a lot of fatty foods. You can lower your cholesterol by exercising more and eating more fruits and vegetables. You also may need to take medicine to lower your cholesterol.

Triglycerides are a form of fat and a major source of energy for the body. This test measures the amount of triglycerides in the blood. Most triglycerides are found in fat (adipose) tissue, but some triglycerides circulate in the blood to provide fuel for muscles to work. After a person eats, an increased level of triglycerides is found in the blood as the body converts the energy not needed right away into fat. Triglycerides move via the blood from the gut to adipose tissue for storage. In between meals, triglycerides are released from fat tissue to be used as an energy source for the body. Most triglycerides are carried in the blood by lipoproteins called very low density lipoproteins (VLDL). High levels of triglycerides in the blood are associated with an increased risk of developing cardiovascular disease (CVD), although the reason for this is not well understood. Certain factors can contribute to high triglyceride levels and to risk of CVD, including lack of exercise, being overweight, smoking cigarettes, consuming excess alcohol, and medical conditions such as diabetes and kidney disease.

This test is performed to see how much phosphorus in your blood. Kidney, liver, and certain bone diseases can cause abnormal phosphorus levels.

Serum progesterone is a test to measure the amount of progesterone in the blood. Progesterone is a hormone produced mainly in the ovaries. In women, progesterone plays a vital role in pregnancy. After an egg is released by the ovaries (ovulation), progesterone helps make the uterus ready for implantation of a fertilized egg. It prepares the womb (uterus) for pregnancy and the breasts for milk production. Men produce some amount of progesterone, but it probably has no normal function except to help produce other steroid hormones.

In many cases, measurement of total testosterone provides the doctor with adequate information. However, in certain cases, for example when the level of SHBG is abnormal, a test for free or bioavailable testosterone may be performed as it may more accurately reflect the presence of a medical condition.

A testosterone test measures the amount of the male hormone, testosterone, in the blood. Both men and women produce this hormone. In males, the testicles produce most of the testosterone in the body. Levels are most often checked to evaluate signs of low testosterone: In boys -- early or late puberty and in men -- impotence, low level of sexual interest, infertility, thinning of the bones In females, the ovaries produce most of the testosterone and levels are most often checked to evaluate signs of higher testosterone levels, such as: decreased breast size, excess hair growth, increased size of the clitoris. irregular or absent menstrual periods and male-pattern baldness or hair thinning.

A TSH test is a lab test that measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland. It tells the thyroid gland to make and release thyroid hormones into the blood.

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks. These include liver, anchovies, mackerel, dried beans and peas, and beer. Most uric acid dissolves in blood and travels to the kidneys. From there, it passes out in urine. If your body produces too much uric acid or doesn't remove enough if it, you can get sick. A high level of uric acid in the blood is called hyperuricemia.

Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. The chemical structures of the types of vitamin D are slightly different, and they are named vitamin D2 (ergocalciferol, which comes from plants) and vitamin D3 (cholecalciferol, which comes from animals). The D2 form is found in fortified foods and in most vitamin preparations and supplements. Vitamin D3 is the form produced in the body and is also used in some supplements. Vitamin D2 and D3 are equally effective when they are converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.

Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. The chemical structures of the types of vitamin D are slightly different, and they are named vitamin D2 (ergocalciferol, which comes from plants) and vitamin D3 (cholecalciferol, which comes from animals). The D2 form is found in fortified foods and in most vitamin preparations and supplements. Vitamin D3 is the form produced in the body and is also used in some supplements. Vitamin D2 and D3 are equally effective when they are converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.