LOINC registered trademark logo from Regenstrief

Logical Observation Identifiers Names and Codes (LOINC®) is the international standard for identifying health measurements, observations, and documents. It provides a common language to unambiguously identify things you can measure or observe that enables the exchange and aggregation of clinical results for care delivery, outcomes management, and research. LOINC is a rich catalog of measurements, including laboratory tests, clinical measures like vital signs and anthropometric measures, standardized survey instruments, and more.

Reference labs, healthcare organizations, U.S. federal agencies, insurance companies, software vendors, in vitro diagnostic testing companies, and more than 82,200 registered users from 175 countries use LOINC to move data seamlessly between systems.

LOINC is developed by Regenstrief Institute, a dynamic, people-centered research organization driven by a mission to connect and innovate for better health.


The following Lab Tests Online test articles provide LOINC information. Please locate by clicking on Health Professional - LOINC from the "Choose Topic" menu.

  • AFB - /acid-fast-bacillus-afb-testing
  • ALT - /alanine-aminotransferase-alt
  • Albumin - /albumin
  • ALP - /alkaline-phosphatase-alp
  • Anti-dsDNA - /anti-dsdna
  • ANA - /antinuclear-antibody-ana
  • ASO - /antistreptolysin-o-aso
  • AST - /aspartate-aminotransferase-ast
  • Bilirubin - /bilirubin
  • Blood Smear - /blood-smear
  • BUN - /blood-urea-nitrogen-bun
  • BNP - /bnp-and-nt-probnp
  • Celiac Tests - /celiac-disease-antibody-tests
  • Chloride - /chloride
  • CRP -/c-reactive-protein-crp
  • CK - /creatine-kinase-ck
  • Creatinine - /creatinine
  • D-Dimer - /d-dimer
  • Epstein Barr - /epstein-barr-virus-ebv-antibody-tests
  • ESR - /erythrocyte-sedimentation-rate-esr
  • eGFR -/estimated-glomerular-filtration-rate-egfr
  • Ferritin - /ferritin
  • GGT - /gamma-glutamyl-transferase-ggt
  • Glucose - /glucose-tests
  • HDL- /hdl-cholesterol
  • HCT - /hematocrit
  • Hemglobin - /hemoglobin
  • A1c - /hemoglobin-a1c
  • hs-CRP - /high-sensitivity-c-reactive-protein-hs-crp
  • Lactate - /lactate
  • LD - /lactate-dehydrogenase-ld
  • LDL - /ldl-cholesterol
  • Mono - /mononucleosis-mono-test
  • PTT- /partial-thromboplastin-time-ptt-aptt
  • Platelet - /platelet-count
  • hCG- /pregnancy-test-hcg
  • PT/INR - /prothrombin-time-and-international-normalized-ratio-ptinr
  • RBC - /red-blood-cell-count-rbc
  • T3 - /t3-free-and-total
  • T4 - /t4-free
  • TSH - /thyroid-stimulating-hormone-tsh
  • TP - /total-protein-and-albuminglobulin-ag-ratio
  • TIBC - /transferrin-and-iron-binding-capacity-tibc-uibc
  • Troponin - /troponin
  • Urine Albumin - /urine-albumin-and-albumin-creatinine-ratio
  • Urine culture - /urine-culture
  • Urine Protein - /urine-protein-and-urine-protein-creatinine-ratio
  • Vitamin D - /vitamin-d-tests
  • WBC - /white-blood-cell-count-wbc
  • WBC Differential - /white-blood-cell-wbc-differential