Blood Test Glossary: Abbreviations Explained

CBC, TSH, CRP, GGT, MCV, eGFR, A1C… What does each abbreviation on your lab report mean? Here is a clear dictionary of the most common ones, each linked to its detailed guide.

Updated June 25, 2026Published by Smart Medical Care SAS

A

AFP — Alpha-fetoprotein: Tumor marker (liver) and pregnancy marker.
Albumin — Serum albumin: Main protein in the blood (nutrition, liver).
Albuminuria (ACR) — Urine albumin-to-creatinine ratio: Albumin in the urine; an early kidney marker.
ALP — Alkaline phosphatase: Liver and bone enzyme.
ALT — Alanine aminotransferase: Liver-specific transaminase (cell injury).
Amylase — Serum amylase: Pancreatic and salivary enzyme.
Anti-TPO antibodies — Anti-thyroid peroxidase antibodies: Thyroid autoantibodies (Hashimoto's).
aPTT — Activated partial thromboplastin time: Clotting test (heparin, factor deficiencies).
AST — Aspartate aminotransferase: Transaminase (liver, muscle, heart).

B

Beta-hCG — Human chorionic gonadotropin: Pregnancy hormone; also a tumor marker.
Bicarbonate — Bicarbonate (HCO₃⁻): Acid-base balance of the blood.
Bilirubin — Total/conjugated bilirubin: Bile pigment; jaundice.
Blood glucose — Blood glucose: Diabetes screening and monitoring.
BNP / NT-proBNP — B-type natriuretic peptide: Marker of heart failure.
BUN — Blood urea nitrogen: Nitrogen waste product; a kidney-function marker.

C

CA 125 — Carbohydrate antigen 125: Tumor marker (ovary).
CA 15-3 — Carbohydrate antigen 15-3: Tumor marker (breast).
CA 19-9 — Carbohydrate antigen 19-9: Tumor marker (pancreas, digestive tract).
Calcium — Serum calcium: Blood calcium (bones, muscles, nerves).
CBC — Complete blood count: Count of the blood's cells.
CEA — Carcinoembryonic antigen: Tumor marker used for follow-up (notably digestive cancers).
Chloride — Serum chloride: Electrolyte on the metabolic panel.
CK / CPK — Creatine kinase: Muscle and heart enzyme.
Creatinine — Serum creatinine: Kidney function; used to calculate eGFR.
CRP — C-reactive protein: Marker of inflammation and infection.

D

D-dimer — Fibrin degradation products: Helps rule out clot/embolism.

E

eGFR — Estimated glomerular filtration rate: Central indicator of kidney function.
Electrolyte panel — Blood electrolyte panel: Sodium, potassium, chloride, bicarbonate.
ESR — Erythrocyte sedimentation rate: Marker of inflammation (nonspecific).
Estradiol — Estradiol (E2): Main estrogen hormone.

F

Ferritin — Serum ferritin: Reflects the body's iron stores.
Fibrinogen — Coagulation factor I: Clotting; also an inflammation marker.
Folate (B9) — Folic acid / vitamin B9: Vitamin; anemia, pregnancy.
Free T3 (FT3) — Free triiodothyronine: Active thyroid hormone.
Free T4 (FT4) — Free thyroxine: Thyroid hormone.
FSH — Follicle-stimulating hormone: Fertility hormone (ovary/testis).

G

GGT — Gamma-glutamyl transferase: Liver enzyme (liver, bile ducts, alcohol).

H

HbA1c — Glycated hemoglobin: Diabetes control over ~3 months.
HDL — High-density lipoprotein: "Good" cholesterol (protective).
Hematocrit (Hct) — Hematocrit: Proportion of red cells in the blood.
Hgb — Hemoglobin: Oxygen-carrying protein; anemia.
Homocysteine — Serum homocysteine: Amino acid; vascular risk, B9/B12 deficiency.

I

INR — International Normalized Ratio: Standardized PT; warfarin monitoring.
Insulin — Serum insulin: Hormone that regulates blood glucose.

L

LDH — Lactate dehydrogenase: Cell-breakdown enzyme (nonspecific).
LDL — Low-density lipoprotein: "Bad" cholesterol (cardiovascular risk).
LH — Luteinizing hormone: Reproductive hormone.
Lipase — Serum lipase: Pancreatic enzyme (pancreatitis).

M

Magnesium — Serum magnesium: Electrolyte (muscles, nerves, heart).
MCH — Mean corpuscular hemoglobin: CBC index.
MCHC — Mean corpuscular hemoglobin concentration: CBC index (redness of red cells).
MCV — Mean corpuscular volume: Size of red blood cells (types of anemia).

P

Phosphate — Serum phosphate: Bones, kidneys, calcium-phosphate balance.
Platelets (PLT) — Platelets (thrombocytes): Clotting (low/high platelet count).
Potassium (K) — Serum potassium: Electrolyte essential to the heart.
Progesterone — Serum progesterone: Hormone of the cycle and pregnancy.
Prolactin — Serum prolactin: Lactation hormone.
PSA — Prostate-specific antigen: Prostate marker.
PT — Prothrombin time: Clotting; reported as INR.
PTH — Parathyroid hormone: Regulates calcium (parathyroid glands).

R

RBC — Red blood cells: Oxygen transport; anemia.
Reticulocytes — Reticulocytes: Young red blood cells (regeneration).

S

Serum iron — Serum iron: Iron circulating in the blood.
Sodium (Na) — Serum sodium: Water and salt balance.

T

TIBC — Total iron-binding capacity: Iron-carrying capacity (transferrin).
Total cholesterol — Total cholesterol: Sum of LDL, HDL and other fractions.
Total protein — Total serum protein: All proteins in the blood.
TRAb — TSH receptor antibodies: Graves' disease (hyperthyroidism).
Transferrin — Transferrin: Iron-transport protein.
Triglycerides — Triglycerides: Fats in the blood (diet, alcohol).
Troponin — Cardiac troponin: Marker of heart attack (myocardial infarction).
TSAT — Transferrin saturation: Availability of iron in the blood.
TSH — Thyroid-stimulating hormone: Hormone that regulates the thyroid.

U

Uric acid — Uric acid (serum): Purine breakdown product; linked to gout.

V

Vitamin B12 — Cobalamin: Vitamin; nerves, anemia.
Vitamin D — 25-OH vitamin D: Bones, immunity; deficiency is common.

W

WBC — White blood cells: Immune defense; infections.

Disclaimer. These definitions are provided for information only. They are not medical advice: interpreting your results depends on your context and belongs to your clinician.

Go further: the reference-range table, the unit converter, or our guides by marker.