| Abbreviation | Meaning |
|---|
| L | leukocytes
lumbar vertebrae (L1 to L5) |
| L&D | labor and delivery |
| LA | left atrium
lymphadenopathy
local anesthetic |
| LAAM | L-alpha-acetylmethadol |
| Lab | laboratory (in health care, usually referring to clinical laboratory) |
| LABA | long-acting beta agonist |
| LABBB | left anterior bundle branch block |
| Lac | laceration
lactate |
| LAD | left anterior descending (a coronary artery)
leukocyte adhesion deficiency
left axis deviation (see electrocardiogram)
lymphadenopathy |
| LAE | left atrial enlargement |
| LAH | left anterior hemiblock |
| LAHB | left anterior hemiblock |
| Lam | laminectomy |
| LAN | lymphadenopathy |
| LAP | leukocyte alkaline phosphatase |
| Lap | laparotomy |
| Lap appy | laparoscopic appendectomy |
| LAR | low anterior resection |
| LARP | left → anterior, right → posterior (path of the vagi as they wander from thorax to abdomen) |
| LAS | lymphadenopathy syndrome |
| Lat | lateral |
lb
LB | pound or pounds (mass) |
| LBBB | left bundle branch block |
| LBO | large bowel obstruction |
| LBP | low back pain |
| LBW | low birth weight |
| LCA | left coronary artery |
| LCHAD | long-chain 3-hydroxyacyl-coenzyme A dehydrogenase |
| LCIS | lobular carcinoma in situ |
| LCM | lymphocytic meningitis |
| LCMV | lymphocytic choriomeningitis virus |
| LCP | Liverpool Care Pathway for the Dying Patient |
| LCPD | Legg–Calvé–Perthes disease |
| LCV | leukocytoclastic vasculitis |
| LCX | left circumflex artery |
| L&D | labor and delivery |
| LDH | lactate dehydrogenase |
| LDL | low-density lipoprotein |
| LDL-C | low-density lipoprotein cholesterol |
| L-DOPA | levo-dihydroxyphenylalanine |
| LEC | lupus erythematosus cell |
| LEEP | loop electrical excision procedure |
| LES | lower esophageal sphincter
lupus erythematosus systemicus |
| LE | lupus erythematosus
lower extremity (human leg) |
| leu | leukocytes |
| LFT | liver function test |
| LGA | large for gestational age |
| LGL | Lown–Ganong–Levine syndrome |
| LGM | lymphogranulomatosis maligna |
| LGSIL | low-grade squamous intraepithelial lesion |
| LGV | lymphogranuloma venereum |
| LH | luteinizing hormone
lightheadedness |
| LHC | left heart catheterization |
| LHRH | luteinizing hormone–releasing hormone |
| Lig | ligament |
| LIH | left inguinal hernia |
| LLD | leg length discrepancy |
| LLE | left lower extremity |
| LLETZ | large loop excision of the transformation zone |
| LLL | left lower lobe |
| LLQ | left lower quadrant |
| LM | left main |
| LMA | left mentoanterior (fetal position)
laryngeal mask airway |
| LMCA | left main coronary artery |
| LMD | local medical doctor |
| LMP | last menstrual period—first day of the menstrual period
low malignant potential |
| LMWH | low-molecular-weight heparin |
| LN | lymph node
Logical Observation Identifiers Names and Codes (LOINC) |
| LND | lymph node dissection |
| LNG | levonorgestrel |
| LNI | lymph node involvement |
| LOA | left occipitoanterior (fetal position)
level of activity
lysis of adhesions Loss of Appetite |
| LOC | loss of consciousness
level of consciousness (e.g., "altered LOC from head trauma") |
| LOF | leakage of fluid |
| LOH | loss of heterozygosity |
| LOI | loss of imprinting |
| LOL | little old lady (often LOL in NAD—see House of God)
lymph-obligatory load |
| LOM | limitation of motion |
| LOP | left occiput posterior (fetal position) |
| LORTA | loss of resistance to air (in anesthesiology; when placing epidural, LORTA indicates entrance of needle to epidural space) |
| LOS | length of stay |
| Lot | lotion |
| LOT | left occiput transverse (fetal position) |
| Lp | lipoprotein |
| LP | lumbar puncture |
| LPH | left posterior hemiblock (see heart block) |
| LPL | lipoprotein lipase |
| LPP | lichen planopilaris |
| LQTS | long QT syndrome |
| L/S | lecithin-to-sphingomyelin ratio |
| LS | lichen sclerosus
Lynch syndrome |
| LSA | lichen sclerosis et atrophicus |
| LSB | left sternal border |
| LSCS | Lower segment Caesarean section |
| LSCTA | lung sounds clear to auscultation |
| LSIL | low-grade squamous intraepithelial lesion |
| LST | laterally spreading tumor |
| LR | lactated Ringer's solution |
| LRINEC | Laboratory Risk Indicator for Necrotizing Soft Tissue Infections Score |
| LRTI | lower respiratory tract infection |
| LT | heat-labile enterotoxin |
| LTAC | long-term acute care |
| LTCS | low transverse cesarean section |
| LUL | left upper lobe (of lung) |
| LUQ | left upper quadrant (of abdomen) |
| LUS | lower uterine segment |
| LUTS | lower urinary tract symptoms |
| LV | left ventricle |
| LVAD | left ventricular assist device |
| LVEDP | left ventricular end diastolic pressure |
| LVEF | left ventricular ejection fraction |
| LVF | left ventricular failure |
| LVH | left ventricular hypertrophy |
| LVOT | left ventricular outflow tract |
| LVP | Large volume paracentesis |
| LWBS | left without being seen |
| Lx of ch | laxative of choice |
| Ly | lymphocytes |
| lytes | electrolytes |