Lab tests

Cholesterol and fats

• Total cholesterolTotal cholesterol is the sum of LDL (“bad”), HDL (“good”) and the other fractions.
• LDL cholesterolLDL is the “bad” cholesterol: particles that carry cholesterol to the tissues and can build up in the walls of blood vessels.
• HDL cholesterolHDL is the “good” cholesterol: particles that carry cholesterol from the tissues back to the liver.
• TriglyceridesTriglycerides are the main form of fat in the blood.

Blood sugar

• GlucoseGlucose is the level of sugar in the blood at the moment the sample is drawn.
• HbA1c (glycated hemoglobin)HbA1c, glycated hemoglobin, reflects the average blood sugar over the last 2–3 months.
• InsulinInsulin is a hormone made by the pancreas that helps cells take in glucose from the blood.

Iron

• Iron, serumSerum iron is how much iron is in the blood right now.
• FerritinFerritin is the protein that stores iron.
• TransferrinTransferrin is the protein that carries iron in the blood.
• Total iron-binding capacity (TIBC)Total iron-binding capacity is how much iron the blood can carry.
• Transferrin saturationTransferrin saturation is the share of transferrin that is carrying iron right now.

Thyroid

• TSH (thyroid-stimulating hormone)TSH, thyroid-stimulating hormone, is a pituitary hormone that controls the thyroid gland.
• Free T4Free T4 is the thyroid’s main hormone in its free form, not bound to proteins, which the tissues can use.
• Free T3Free T3 is the most active thyroid hormone; most of it is made from T4.

Vitamins

• Vitamin D, 25-OHVitamin D, 25-OH, is the main form used to assess the body’s vitamin D.
• Vitamin B12Vitamin B12 is needed to make red blood cells and for the nervous system.
• Folate (folic acid, B9)Folate (folic acid, vitamin B9) is needed for cell division and to make red blood cells.

Kidneys

• CreatinineCreatinine is a waste product of muscle metabolism that the kidneys clear.
• eGFR (estimated glomerular filtration rate)eGFR, the estimated glomerular filtration rate, is an estimate of how much blood the kidneys filter per minute.
• UreaUrea is the end product of protein metabolism, cleared by the kidneys.
• Urea nitrogen (BUN)Blood urea nitrogen (BUN) is the same thing as urea, on a different scale: the one used in the US.
• Uric acidUric acid is a breakdown product of purines, from food and from the body’s own cells.

Minerals

• CalciumCalcium is a mineral for bones, muscles and nerves.
• MagnesiumMagnesium is a mineral that muscles, nerves and hundreds of enzymes need to work.
• Phosphate (phosphorus)Phosphate, inorganic phosphorus, is a mineral that builds bones together with calcium and takes part in energy metabolism.

Hormones

• TestosteroneTestosterone is the main male sex hormone; women have it too, in smaller amounts.
• EstradiolEstradiol is the main female sex hormone.
• CortisolCortisol is a hormone made by the adrenal glands.
• ProlactinProlactin is a pituitary hormone responsible for milk production.

Blood count

• MCHC (mean corpuscular hemoglobin concentration)MCHC, mean corpuscular hemoglobin concentration, is the average concentration of hemoglobin in red blood cells: how “saturated” the cells are with hemoglobin.
• RDW (red cell distribution width)RDW, red cell distribution width, shows how much red blood cells differ in size.
• Hemoglobin (Hb)Hemoglobin is the protein in red blood cells that carries oxygen.

Liver

• Bilirubin, totalBilirubin is a breakdown product of hemoglobin that the liver processes.
• ALT (alanine aminotransferase)ALT is an enzyme found mostly in liver cells.
• AST (aspartate aminotransferase)AST is an enzyme of the liver, heart and muscles.

Inflammation

• CRP (C-reactive protein)C-reactive protein (CRP) is a protein the liver makes in response to inflammation.