Health education
Plain-language explanations of every biomarker we test — what it measures, why it matters, normal ranges, and which tests include it.
Showing 42 of 42 biomarkers
What it measures
The total number of red blood cells per volume of blood. Red blood cells carry oxygen from your lungs to every tissue in your body.
Why it matters
Low RBC can indicate anemia, blood loss, or nutritional deficiencies. High RBC may signal dehydration or a bone marrow disorder.
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What it measures
The protein inside red blood cells that binds to oxygen and gives blood its red color.
Why it matters
Low hemoglobin is the hallmark of anemia and causes fatigue, shortness of breath, and weakness. High levels may indicate polycythemia.
What it measures
The percentage of your blood volume that is made up of red blood cells.
Why it matters
A low hematocrit confirms anemia. A high hematocrit can thicken the blood and increase clotting risk.
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What it measures
The total count of immune cells in your blood. White blood cells defend the body against infection and foreign invaders.
Why it matters
Elevated WBC often signals infection, inflammation, or immune activation. Very low WBC can indicate bone marrow suppression or autoimmune disease.
What it measures
Tiny cell fragments that clump together to form clots and stop bleeding when a blood vessel is injured.
Why it matters
Low platelets (thrombocytopenia) increase bleeding risk. High platelets can raise the risk of abnormal clotting.
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What it measures
The average size of your red blood cells.
Why it matters
Small red blood cells (low MCV) suggest iron deficiency. Large red blood cells (high MCV) point to B12 or folate deficiency.
What it measures
The primary sugar your body uses for energy, derived from the food you eat.
Why it matters
Persistently elevated glucose is the defining feature of diabetes and prediabetes. Low glucose (hypoglycemia) can cause dizziness, confusion, and fainting.
What it measures
A measure of average blood sugar over the past 2–3 months, based on how much glucose has attached to hemoglobin.
Why it matters
The gold standard for diagnosing and monitoring diabetes and prediabetes. Unlike a fasting glucose test, it reflects long-term blood sugar control.
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What it measures
A waste product produced by muscle metabolism, filtered out of the blood by the kidneys.
Why it matters
Elevated creatinine is a reliable indicator of reduced kidney function. It rises when the kidneys are not filtering waste efficiently.
What it measures
An estimate of how well your kidneys are filtering waste from the blood, calculated from creatinine, age, and sex.
Why it matters
eGFR is the primary measure of kidney function. Values below 60 for more than 3 months indicate chronic kidney disease.
What it measures
A waste product from protein breakdown, filtered by the kidneys. BUN reflects both kidney function and protein metabolism.
Why it matters
High BUN can indicate kidney disease, dehydration, or high protein intake. Low BUN may suggest liver disease or malnutrition.
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What it measures
An enzyme found mainly in the liver. When liver cells are damaged, ALT leaks into the bloodstream.
Why it matters
Elevated ALT is one of the earliest signs of liver damage from fatty liver disease, hepatitis, alcohol use, or medications.
What it measures
An enzyme found in the liver, heart, and muscles. Like ALT, it rises when these tissues are damaged.
Why it matters
Elevated AST alongside ALT strongly suggests liver disease. AST alone may indicate heart or muscle damage.
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What it measures
An enzyme produced by the liver, bile ducts, and bones.
Why it matters
High ALP can indicate bile duct obstruction, liver disease, or bone disorders. It is often elevated in gallbladder disease.
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What it measures
A yellow pigment produced when red blood cells break down, processed and excreted by the liver.
Why it matters
High bilirubin causes jaundice (yellowing of skin and eyes) and can indicate liver disease, bile duct obstruction, or hemolytic anemia.
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What it measures
Total protein measures all proteins in the blood. Albumin is the most abundant, made by the liver and responsible for maintaining fluid balance.
Why it matters
Low albumin is a sensitive marker of malnutrition, liver disease, or kidney disease (protein loss in urine).
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What it measures
The primary electrolyte in blood and fluid outside cells. It regulates fluid balance, blood pressure, and nerve and muscle function.
Why it matters
Abnormal sodium levels affect brain function. Low sodium (hyponatremia) can cause confusion and seizures. High sodium (hypernatremia) causes dehydration.
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What it measures
An electrolyte critical for heart rhythm, muscle contraction, and nerve signaling.
Why it matters
Both high and low potassium can cause dangerous heart arrhythmias. It is closely monitored in patients on diuretics or with kidney disease.
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What it measures
The most abundant mineral in the body, essential for bone strength, muscle contraction, nerve transmission, and blood clotting.
Why it matters
High calcium (hypercalcemia) can indicate hyperparathyroidism or cancer. Low calcium (hypocalcemia) causes muscle cramps and bone loss.
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What it measures
The total amount of all cholesterol types in your blood, including LDL, HDL, and VLDL.
Why it matters
High total cholesterol is a major risk factor for heart disease and stroke, though the ratio of LDL to HDL matters more than the total alone.
What it measures
Low-density lipoprotein — often called "bad" cholesterol. LDL carries cholesterol to artery walls where it can build up as plaque.
Why it matters
High LDL is the primary driver of atherosclerosis (artery hardening) and is the main target of cholesterol-lowering medications.
What it measures
High-density lipoprotein — often called "good" cholesterol. HDL carries cholesterol away from arteries back to the liver for removal.
Why it matters
Higher HDL is protective against heart disease. Low HDL is an independent risk factor for cardiovascular events.
What it measures
A type of fat (lipid) in the blood. After eating, your body converts unused calories into triglycerides and stores them in fat cells.
Why it matters
High triglycerides are linked to heart disease, metabolic syndrome, and pancreatitis. They are strongly influenced by diet, alcohol, and exercise.
What it measures
A protein produced by the liver in response to inflammation anywhere in the body.
Why it matters
Elevated CRP signals active inflammation from infection, injury, or chronic disease. High-sensitivity CRP (hs-CRP) is used to assess cardiovascular risk.
What it measures
An amino acid produced during protein metabolism. Elevated levels are associated with damage to blood vessel walls.
Why it matters
High homocysteine is an independent risk factor for heart attack, stroke, and blood clots — even when cholesterol levels appear normal.
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What it measures
The total amount of testosterone in the blood, including both bound and unbound forms.
Why it matters
Low testosterone in men causes fatigue, low libido, muscle loss, and mood changes. In women, abnormal levels can affect menstrual cycles and fertility.
What it measures
The small fraction of testosterone not bound to proteins — the biologically active form that cells can actually use.
Why it matters
Free testosterone is a more accurate indicator of hormonal status than total testosterone. A man can have normal total testosterone but low free testosterone and still experience symptoms.
What it measures
A protein that binds to sex hormones (testosterone and estrogen) in the blood, controlling how much is available to tissues.
Why it matters
High SHBG reduces the amount of free testosterone available, which can cause low-T symptoms even when total testosterone is normal.
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What it measures
A hormone from the pituitary gland that signals the thyroid to produce thyroid hormones. TSH is the most sensitive indicator of thyroid function.
Why it matters
High TSH indicates an underactive thyroid (hypothyroidism). Low TSH indicates an overactive thyroid (hyperthyroidism). Both affect energy, weight, mood, and metabolism.
What it measures
The primary form of estrogen in the body, produced mainly by the ovaries in women and in smaller amounts by the testes and adrenal glands in men.
Why it matters
In women, estradiol regulates the menstrual cycle, bone density, and cardiovascular health. In men, abnormally high estradiol can cause gynecomastia and low libido.
What it measures
A hormone produced by the liver in response to growth hormone (GH). IGF-1 is the primary mediator of growth hormone effects on the body.
Why it matters
Low IGF-1 can indicate growth hormone deficiency, causing fatigue, reduced muscle mass, and poor recovery. High levels may be associated with acromegaly.
What it measures
A hormone produced by cells in ovarian follicles. AMH levels directly reflect the number of remaining eggs (ovarian reserve).
Why it matters
AMH is the most reliable marker of fertility potential in women. Low AMH indicates diminished ovarian reserve. It is also used to assess polycystic ovary syndrome (PCOS).
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What it measures
A protein that stores iron inside cells. Blood ferritin levels reflect total body iron stores.
Why it matters
Ferritin is the most sensitive test for iron deficiency — it falls before anemia develops. High ferritin can indicate iron overload, inflammation, or liver disease.
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What it measures
The amount of iron circulating in the blood bound to transferrin (the transport protein).
Why it matters
Low serum iron combined with low ferritin confirms iron deficiency. High serum iron may indicate iron overload (hemochromatosis).
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What it measures
A measure of how much iron the blood could carry if all transferrin proteins were fully loaded.
Why it matters
High TIBC with low iron and ferritin confirms iron deficiency anemia. Low TIBC may suggest iron overload or chronic disease.
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What it measures
An essential vitamin required for nerve function, DNA synthesis, and red blood cell formation. It is found almost exclusively in animal products.
Why it matters
B12 deficiency causes fatigue, nerve damage (tingling, numbness), memory problems, and megaloblastic anemia. It is common in vegans and older adults.
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What it measures
A B vitamin essential for DNA synthesis, cell division, and red blood cell production. Critical during pregnancy for fetal neural tube development.
Why it matters
Folate deficiency causes megaloblastic anemia and, during pregnancy, significantly increases the risk of neural tube defects in the baby.
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What it measures
A test that measures how quickly red blood cells settle to the bottom of a tube. Inflammation causes proteins to make cells clump and fall faster.
Why it matters
Elevated ESR is a non-specific marker of inflammation, infection, or autoimmune disease. It is used to monitor conditions like rheumatoid arthritis and lupus.
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What it measures
Antibodies that mistakenly target proteins inside the cell nucleus. A positive ANA is the hallmark finding in many autoimmune diseases.
Why it matters
A positive ANA with a high titer strongly suggests an autoimmune condition such as lupus (SLE), Sjögren's syndrome, or rheumatoid arthritis.
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What it measures
PT measures how long blood takes to clot via the extrinsic pathway. INR is a standardized ratio that allows results to be compared across labs.
Why it matters
Elevated PT/INR means blood clots more slowly, increasing bleeding risk. It is used to monitor patients on blood thinners like warfarin and to assess liver function.
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What it measures
The level of insulin in the blood after an overnight fast. Insulin is the hormone that allows glucose to enter cells.
Why it matters
Elevated fasting insulin is the earliest sign of insulin resistance — often detectable years before blood sugar rises. It is a key marker of metabolic syndrome.
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What it measures
A small amount of the protein albumin in the urine. Healthy kidneys do not allow albumin to pass into urine.
Why it matters
Microalbuminuria is the earliest detectable sign of diabetic kidney disease (nephropathy), often appearing years before kidney function declines.
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