Abbreviations and acronyms used in LOINC (KB)

This is an alphabetical list of the abbreviations and acronyms used across LOINC. It is a work in progress and, to date, primarily contains abbreviations/acronyms used in various LOINC Parts, except for Components.

The list does not include combinations of abbreviations and acronyms that are separated by a delimiter (e.g. Ser/Plas, Ser+CSF) since we have many such combinations in LOINC. To learn more about the use and meaning of delimiters in various parts of a LOINC term, please refer to Section 2 of the LOINC Users’ Guide.

This list also does not include abbreviations used in the Class field. You can find exhaustive lists of Class values by Class Type in Appendix B of the Users’ Guide.

If you have a specific abbreviation or acronym that you were looking for that is not in this list, please contact us.

Abbreviation/Acronym	Meaning	Areas of LOINC
1.5H	1.5 hours	Timing; Challenge timing
100D	100 days	Timing
10D	10 days	Timing; Challenge timing
10H	10 hours	Timing
10M	10 minutes	Timing; Challenge timing
10Y	10 years	Timing
12H	12 hours	Timing; Challenge timing
12Mo	12 months	Timing
14D	14 days	Timing
15M	15 minutes	Timing; Challenge timing
180D	180 days	Timing
18H	18 hours	Timing
1D	1 day	Timing
1H	1 hour	Timing; Challenge timing
1M	1 minute	Timing; Challenge timing
1Mo	1 month	Timing; Challenge timing
1W	1 week	Timing; Challenge timing
1Y	1 year	Timing
2.5H	2.5 hours	Timing; Challenge timing
20M	20 minutes	Timing; Challenge timing
24H	24 hours	Timing; Challenge timing
25M	25 minutes	Timing; Challenge timing
2D	2 days	Timing; Challenge timing
2H	2 hours	Timing; Challenge timing
2M	2 minutes	Timing; Challenge timing
2Mo	2 months	Timing; Challenge timing
2W	2 weeks	Timing; Challenge timing
2Y	2 years	Timing
30D	30 days	Timing
30M	30 minutes	Timing; Challenge timing
3D	3 days	Timing; Challenge timing
3H	3 hours	Timing; Challenge timing
3-HPMA	3-Hydroxypropyl Mercapturic acid	Component
3M	3 minutes	Timing; Challenge timing
3Mo	3 months	Timing; Challenge timing
3W	3 weeks	Timing; Challenge timing
3Y	3 years	Timing
45M	45 minutes	Timing
48H	48 hours	Timing
4D	4 days	Timing; Challenge timing
4H	4 hours	Timing; Challenge timing
4M	4 minutes	Timing; Challenge timing
4W	4 weeks	Timing; Challenge timing
5D	5 days	Timing; Challenge timing
5H	5 hours	Timing; Challenge timing
5M	5 minutes	Timing; Challenge timing
6D	6 days	Timing; Challenge timing
6H	6 hours	Timing; Challenge timing
6M	6 minutes	Timing; Challenge timing
6Mo	6 months	Timing
72H	72 hours	Timing
7D	7 days	Timing; Challenge timing
7H	7 hours	Timing; Challenge timing
7M	7 minutes	Timing; Challenge timing
8H	8 hours	Timing; Challenge timing
8M	8 minutes	Timing; Challenge timing
90D	90 days	Timing
90M	90 minutes	Timing
9H	9 hours	Timing
9M	9 minutes	Timing; Challenge timing
Ab	Antibody	Component
AC	Abdominal circumference	Method
Accel	Acceleration	Property
ACnc	Arbitrary concentration	Property
ACnt	Arbitrary content	Property
Addr	Address	Property
ADL	Activities of daily living	Component
AFr	Arbitrary fraction	Property
Ag	Antigen	Component
Aggl	Agglutination	Method
Amnio fld	Amniotic fluid	System
Anat	Anatomy	Property
Angio	Angiography	Method
AP	Apply Externally	Challenge route
Aper	Appearance	Property
ArArea	Area/Area	Property
ARat	Arbitrary Rate	Property
Arb	Arbitrary	Property
AreaFr	Area Fraction	Property
AreaRto	Area Ratio	Property
ArEnrg	Energy/Area	Property
ArLen	Length/Area	Property
ArMass	Mass/Area	Property
ArResis	Resistance/Area	Property
ArVol	Volume/Area	Property
ArVRat	Volume Rate/Area	Property
ASHA NOMS	ASHA National Outcomes Measurement System	Method
Asp	Aspirate	System
AUC	Area under the curve	Property
B	Buccal	Challenge route
Bib	Bibliographic Citation	Property
Bil fld	Bile fluid	System
Bld	Whole blood	System
Bld.dot	Dried blood spot	System
BldA	Blood arterial	System
BldC	Blood capillary	System
BldCo	Blood – cord	System
BldL	Blood bag	System
BldMV	Blood- mixed Venous	System
BldP	Blood – peripheral	System
BldV	Blood venous	System
Blood group antibody screen	Blood group antibody screen	Method
Body fld	Body fluid, unsp	System
Bone mar	Marrow (bone)	System
BS	Bishop Score Assessment	Method
CAct	Catalytic Activity	Property
CAS	Coronavirus Anxiety Scale	Method
CBA IFA	Cell binding immunofluorescent assay	Method
CBS-8	Columbia Behavior Scale for Dementia	Method
CCnc	Catalytic Concentration	Property
CCnt	Catalytic Content	Property
CDC	Complement-dependent cytotoxicity	RelatedName
CDC	U.S. Centers for Disease Control and Prevention	Component; Method
CFst	Calorie fast	Challenge
CFr	Catalytic Fraction	Property
CFr.DF	Decimal Catalytic Fraction	Property
Chromo	Chromogenic/Enzymatic Assay	Method
Circ	Circumference	Property
CircFr	Circumference Fraction	Property
CKD-EPI	Creatinine and Cystatin C-based formula	Method
ClockTime	Clock Time	Property
Cmplx	Complex	Property
Cnjt	Conjunctiva	System
Cnl	Cannula	System
CNPI	Checklist of nonverbal pain indicators	Method
Coag	Coagulation Assay	Method (also Class)
Col	Colostrum	System
ColorRto	Color Ratio	Property
COMI	Core Outcome Measures Index	Method
Comp fix	Complement Fixation	Method
Compli	Compliance	Property
CompliRto	Compliance Ratio	Property
COPE	COvid-19 Participant Experience (COPE)	Method
COVEX	COVID-19 Experiences	Method
CRat	Catalytic Rate	Property
CRBS	Coronavirus Racial Bias Scale	Method
Crn	Cornea	System
CRto	Catalytic Ratio	Property
CSF	Cerebral spinal fluid	System
CSub	Catalytic Substance	Property
CT	Computed tomography	Method
CTp	Catheter tip	System
Cvm	Cervical mucus	System
Cvx	Cervix	System
Cyto stain	Cytology Stain	Method
Desc	Description	Property
Dial fld	Dialysis fluid	System
Dial fld prt	Peritoneal dialysis fluid	System
Diam	Diameter	Property
DNA	deoxyribonucleic acid	Component
Doc	Document	Scale
DT	Dental	Challenge route
DtTmRange	Date and Time Range	Property
Duod fld	Duodenal fluid	System
Dur	Duration	Timing
Dx	Diagnosis	Component
EEG	Electroencephalogram	System; Method
Elcur	Electrical current	Property
ElecCon	Electrical Conductivity	Property
Elpot	Electrical Potential (Voltage)	Property
ElpotRat	Voltage Rate (=Amperage)	Property
ElpotRto	Electrical Potential Ratio	Property
EmailAddr	E-mail Address	Property
Enctr	Duration of an encounter (hospital stay, visit).	Timing
Endomet	Endometrium	System
EngCnc	Energy Concentration	Property
EngCnt	Energy Content	Property
EngDiff	Energy Difference	Property
EngFr	Energy Fraction	Property
EngRat	Power = Energy/Time	Property
EngRatFr	Energy Rate Fraction	Property
EngRto	Energy Ratio	Property
Enrg	Energy	Property
EntCat	Entitic Catalytic Activity	Property
EntLen	Entitic Length	Property
EntLogNum	Logarithmic Entitic Number	Property
EntMass	Entitic Mass	Property
EntNum	Entitic Number	Property
EntSRto	Entitic Substance Ratio	Property
EntSub	Entitic Substance	Property
EntVol	Entitic Volume	Property
EP	Epidural	Challenge route
Equ	Equation	Property
ET	Endotrachial Tube	Challenge route
Exhl gas	Exhaled gas (breath)	System
Fcn	Function	Property
FFst	Fluid fast	Challenge
FIGO	International Federation of Gynecology and Obstetrics	Method
Find	Finding	Property
FINDRISC	Finnish Diabetes Risk Score	Method
FL	Femur length	Method
FldConduct	Fluid Conductance	Property
FldResist	Fluid Resistance	Property
Floc	Flocculation Assay	Method
FNA	Fine needle aspiration	System
Freq	Frequency	Property
frst	First value observed during an interval	Timing
Gast fld	Gastric fluid/contents	System
GC-MS	Gas chromatography-mass spectrometry	Method
GE	Greater than or equal to	Component; Timing
Genital fld	Genital fluid	System
Genital loc	Genital lochia	System
Genital muc	Genital mucus	System
Geno	Genotype	Property
GT	Greater than	Timing
Gt 1H	Greater than 1 hour	Timing
GTT	Gastronomy Tube	Challenge route
GU	GU Irrigant	Challenge route
HA	Hemagglutination	Method
HAI	Hemagglutination Inhibition	Method
HC	Head circumference	Method
Head>Cerebral vessels	Head>Cerebral vessels	System
HIV	Human immunodeficiency virus	Component
HLA	Human leukocyte antigen	Component (also Class)
HNA	Human neutrophil alloantigen	Component (also Class)
HOOS-PS	Hip disability and Osteoarthritis Outcome Score – Physical Function Shortform	Method
HPA	Human platelet antigen	Component (also Class)
HSVS	Housing Stability Vital Signs	Method
HTLV 1	human t-cell lymphotropic virus-1	Component
Hx	History	Property
IA	Immunoassay	Method
IA.MTTT	Immunoassay Modified two-tiered testing	Method
IA	Intra-arterial	Challenge route
IADL	Instrumental activities of daily living	Component
IB	Immune Blot	Method
IB	Intrabursal	Challenge route
IC	Intracardiac	Challenge route
ICD	International classification of diseases	Component
ICN	Intracervical (uterus)	Challenge route
ICP	Inductively Coupled Plasma	Method
ID	Identifier	Property
ID	Intradermal	Challenge route
IF	Immune Fluorescence	Method
Ig	immunoglobulin	Component
IgA	immunoglobulin A	Component
IgD	immunoglobulin D	Component
IgE	immunoglobulin E	Component
IgG	immunoglobulin G	Component
IgM	immunoglobulin M	Component
IgV	immunoglobulin V	Component
IH	Inhalation	Challenge route
IHA	Intrahepatic Artery	Challenge route
IM	Intramuscular	Challenge route
Imp	Impression/interpretation of study	Property
IN	Intranasal	Challenge route
Inhl gas	Inhaled gas	System
Instrct	Instructions	Property
Inverse VI	Inverse Inspired Volume	Property
InvLen	Inverse Length	Property
IO	Intraocular	Challenge route
IP	Intraperitoneal	Challenge route
IS	Intrasynovial	Challenge route
IT	Intrathecal	Challenge route
IU	Intrauterine	Challenge route
IV	Intravenous	Challenge route
KOOS-PS	Knee injury and Osteoarthritis Outcome Score – Physical Function Shortform	Method
LA	Latex Agglutination	Method
LaCnc	Log Arbitrary Concentration	Property
Len	Length	Property
LenFr	Length Fraction	Property
LenRto	Length Ratio	Property
LHR	Leukocyte Histamine Release	Method
LKSS	Lysholm Knee Scoring Scale	Method
LnCnc	Log Number Concentration	Property
LnRto	Log Number Ratio	Property
Loc	Location	Property
LogInvPct	Log Inverse Percent	Property
LogLenRto	Log Length Ratio	Property
LogRtoElp	Log Ratio Electrical Potential	Property
Lower extremity.left>Foot subtalar joint	Lower extremity.left>Foot subtalar joint	System
Lower extremity.left>Thigh.soft tissue	Lower extremity.left>Thigh.soft tissue	System
LRat	Length Rate	Property
LsCnc	Log Substance Concentration	Property
Lt 1H	Less than 1 hour	Timing
Lung tiss	Lung tissue	System
max	Maximum value over interval	Timing
MCnc	Mass Concentration	Property
MCncDiff	Difference in Mass Concentration	Property
MCncSq	Mass Concentration Squared	Property
MCnt	Mass Content	Property
MCPctDiff	Percent Difference in Mass Concentration	Property
MDiff	Mass Difference	Property
mean	Mean of all of the values observed on the interval (This is the default selection.)	Timing
Me-PFOSA-AcOH	2-N-Methyl-perfluorooctanesulfonamide acetate	Component
MFr	Mass Fraction	Property
MFr.DF	Mass Decimal Fraction	Property
MFrDiff	Mass Fraction Difference	Property
MIC	Minimum Inhibitory Concentration	Method
MIC.VOC	Minimum Inhibitory Concentration Volatile Organic Compounds	Method
min	Minimum value over interval	Timing
MLC	Minimum Lethal Concentration	Method
MM	Mucus Membrane	Challenge route
Molgen	Molecular Genetics	Method
MoM	Multiple of the Median	Property
Morph	Morphology	Property
MPSS	Mainz Pain Staging System	Method
MR	Magnetic resonance	Method
MRat	Mass Rate	Property
MRatRange	Mass Rate Range	Property
MRC	Medical Research Council	Method
MRto	Mass Ratio	Property
MSCnc	Mass or Substance Concentration	Property
MTH	Mouth/Throat	Challenge route
Multi	“Multi”	Scale
Nar	Narrative	Scale
Naric	Number Aeric (number per area)	Property
NCHC	Norwalk Community Health Center Screening Tool	Method
NCnc	Number Concentration (count/vol)	Property
NCncRange	Number Concentration (count/vol) Range	Property
NCnt	Number Content = Count/Mass	Property
Neut	Virus Neutralization	Method
NFr	Number Fraction	Property
NFr.DF	Decimal number fraction	Property
NG	Nasogastric	Challenge route
NIPS	Neonatal Infant Pain Scale	Method (also Class)
Nom	Nominal	Scale
NOS	not otherwise specified	Component
NP	Nasal Prongs	Challenge route
Nph	Naspopharynx	System
NPP	Non-physician practitioner	Part description
NRat	Number=Count/Time	Property
NRS	Nutritional Risk Screening	Method
NRto	Number Ratio	Property
NS	Nasal	Challenge route
NT	Nasotrachial Tube	Challenge route
Num	Number	Property
NumDiff	Number Difference	Property
NumRange	Number Range	Property
OD	Optical Density	Property
ODI	Oswestry Disability Index	Method
OES	Optical Emission Spectrometry	Method
OP	Ophthalmic	Challenge route
Ord	Ordinal	Scale
OrdQn	Quantitative or Ordinal	Scale
Osmol	Osmolality	Property
OT	Otic	Challenge route
OTH	Other/Miscellaneous	Challenge route
PCFS	Post Covid-19 Functional Status	Method
PctDiff	Percent Difference	Property
Pericard fld	Pericardial fluid	System
Periton fld	Peritoneal fluid /ascites	System
PF	Perfusion	Challenge route
PFOS	perfluorooctane sulfonic acid	Component
Placent	Placenta	System
Plas	Plasma	System
Plr fld	Pleural fluid (thoracentesis fld)	System
Pn	Person Name	Property
PNDS	Perioperative Nursing Data Set	Method
PO	Oral	Challenge route
PPP	Platelet poor plasma	System
PPres	Pressure (partial)	Property
PPresDiff	Difference in Partial Pressure	Property
PPresRto	Partial Pressure Ratio	Property
PR	Rectal	Challenge route
Prctl	Percentile	Property
Pres	Pressure	Property
PresRat	Pressure Rate	Property
PresRto	Pressure Ratio	Property
PressDiff	Difference	Property
Prid	Presence or Identity	Property
Procedure dur	Duration of the procedure (surgery, etc.)	Timing
PROWL	Patient-reported outcomes with LASIK	Method
PRP	Platelet rich plasma	System
PrThr	Presence or Threshold	Property
Pt	To identify measures at a point in time. This is a synonym for “spot” or “random” as applied to urine measurements.	Timing
PT+CT perf	PT+CT.perfusion	Method
pVNT	Pseudovirus Neutralization	Method
Qn	Quantitative	Scale
RAST	Radioallergosorbent test	Method
RatDiff	Rate Difference	Property
RBC	Erythrocytes	System
RBCCo	Red Blood Cells Cord	System
RelACnc	Relative Arbitrary Concentration	Property
RelCCnc	Relative Catalytic Concentration	Property
RelEngRat	Relative Power	Property
RelFldConduct	Relative Fluid Conductance	Property
RelFldResist	Relative Fluid Resistance	Property
RelInvVI	Relative Inverse Volume Inspired	Property
RelMCnc	Relative Mass Concentration	Property
RelMRat	Relative Mass Rate	Property
RelRto	Relative Ratio	Property
RelSCnc	Relative Substance Concentration	Property
RelSoundInt	Relative Sound Intensity	Property
RelSRat	Relative Substance Rate	Property
RelTime	Relative Time	Property
RelVol	Relative Volume	Property
RelVRat	Relative Volume Rate	Property
Resis	Resistance	Property
Resp.lower	Lower respiratory	System
REVEAL	Registry to Evaluate Early and Long-Term PAH Disease Management	Method
RF	Radiofluoroscopy	Method
RFLP	Restriction Fragment Length Polymorphism	Method
RFLP.rRNA	Restriction Fragment Length Polymorphism on rRNA	Method
RIA	Radioimmunoassay	Method
RM	Rebreather Mask	Challenge route
RMDQ	Roland Morris Disability Questionnaire	Method
RNA	ribonucleic acid	Component
RPR	Rapid Plasma Reagin	Method
RptPeriod	Reporting period	Timing
rRNA	ribosomal ribonucleic acid	Component
RT-QuIC	Real-time quaking-induced conversion	Method
RUDAS	Rowland Universal Dementia Assessment Scale	Method
SatFr	Saturation Fraction	Property
SBT	Serum Bacterial Titer	Method
SC	Subcutaneous	Challenge route
SCnc	Substance Concentration	Property
SCncDiff	Difference in Substance Concentration	Property
SCncSq	Substance Concentration Squared	Property
SCnt	Substance Content	Property
ScoreDiff	Score Difference	Property
ScoreRange	Score range	Property
SD	Soaked Dressing	Challenge route
SDOM	Standard Dermatology Outcome Measures	Method
SemiQn	Semiquantitative	Scale
Seq	Nucleotide Sequence	Property
Ser	Serum	System
SFr	Substance Fraction	Property
SFr.DF	Decimal Substance Fraction	Property
SL	Sublingual	Challenge route
SOFA	Sequential Organ Failure Assessment	Method
SPR	Surface plasmon resonance	Method
Sptt	Sputum – tracheal aspirate	System
SRat	Substance Rate	Property
SRto	Substance Ratio	Property
Stdy	Duration of the study	Timing
Sub	Substance Amount	Property
SPR	Surface Plasmon Resonance	Method
Susc	Susceptibility	Property
Synv fld	Synovial fluid (Joint fluid)	System
TAPS	Tobacco, Alcohol, Prescription medications, and other Substance use assessment	Method
TD	Transdermal	Challenge route
Tele	Telephone Number	Property
Temp	Temperature	Property
TempDiff	Temperature Difference	Property
ThrACnc	Threshold Arbitrary Concentration	Property
ThreshNum	Threshold Number	Property
ThrMCnc	Threshold Mass Concentration	Property
ThrSCnc	Threshold Substance Concentration	Property
Thrt	Throat	System
Tigi	Tissue large intestine	System
TimeDif	Difference in Time Duration	Property
TimeFr	Time Fraction	Property
Tiss	Tissue, unspecified	System
TissCo	Cord Tissue	System
Titr	Dilution Factor (Titer)	Property
TL	Translingual	Challenge route
TmElpot	Time Electrical Potential	Property
TmMCnc	Time mass concentration	Property
TmSCnc	Time substance concentration	Property
TmStp	Time Stamp—Date and Time	Property
TmStpRange	Time Stamp Range	Property
TP	Topical	Challenge route
TQ2	Timing Quantity 2	Property
TRA	Tracheostomy	Challenge route
TRH	Thyrotropin-releasing hormone	Challenge route
TRto	Time Ratio	Property
Tscore	T Score	Property
TscoreDiff	T Score Difference	Property
Tsmi	Tissue small intestine	System
Txt	Text	Property
Ulc	Ulcer	System
Unk sub	Unknown substance	System
UR	Urethral	Challenge route
Urethra	Urethra	System
URI	Uniform Resource Identifier	Property
Urine sed	Urine sediment	System
US	Ultrasound	Method
Vag	Vagina	System
VAP	Vertical Auto Profile	Method
VC	Visual Count	Method
VCF	Variant Call File	Property
VCnt	Volume Content	Property
VDRL	Venereal Disease Research Laboratory	Method
Vel	Velocity	Property
VelRat	Velocity Rate	Property
VelRto	Velocity Ratio	Property
VFr	Volume Fraction	Property
VFr.DF	Volume Decimal Fraction	Property
VFrDiff	Difference in Volume Fraction	Property
VG	Vaginal	Challenge route
Visc	Viscosity	Property
Vitr fld	Vitreous Fluid	System
VM	Ventimask	Challenge route
Vol	Volume	Property
VPctDiff	Percent Volume Difference	Property
VRat	Volume Rate	Property
VRatCnt	Volume Rate Content	Property
VRatRto	Volume Rate Ratio	Property
VRto	Volume Ratio	Property
VRtoPctDiff	Percent Volume Ratio Difference	Property
WBC	Leukocytes	System
WHOQOL_BREF	WHO Quality of life-BREF	Method
WND	Wound	Challenge route
Xad	Extended Address	Property
XR.3D	X-ray 3 dimensional	Method
XXX	Not specified	Timing; System
XXX^min	Unspecified time minimum	Timing
Zscore	Zscore	Property
RTS	Revised Trauma Score	Method
Mut Anl	Molgen.targeted mutational analysis	Method