This article contains a list of commonly used medical abbreviations and acronyms that start with the letter L and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order).

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• L

  • fifty (Roman numeral)

  • Latin

  • left

  • length

  • leucine

  • liter

  • lumbar

• L1-L5: lumbar vertebrae

• LA

  • left atrium

  • left auricle

  • local anesthesia

• La: lanthanum

• LAA: left atrial appendage

• LACI: lacunar infarct

• LAD

  • left anterior descending artery

  • left axis deviation

  • lymphadenopathy

• LAE: left atrial enlargement

• LAGB: laparoscopic adjustable gastric banding

• LAO: left anterior oblique

• LAP: laparoscopy/laparoscopic

• LAR: low anterior resection

• LARC: long-acting reversible contraceptive

• LAS

  • levator ani syndrome

  • London Ambulance Service (UK)

• LASH

  • laparoscopic-assisted supracervical hysterectomy

  • long-lasting autonomic symptoms with hemicrania

• LATE: limbic-predominant age-related TDP-43 encephalopathy

• LAUP: laser-assisted uvulopalatoplasty

• LAVH: laparoscopic-assisted vaginal hysterectomy

• LAZ: left apical zone

• LB: loose body

• lb: pound (Latin: libra)

• LBBB: left bundle branch block

• LBO: large bowel obstruction

• LBP

  • low blood pressure

  • low(er) back pain / lumbar back pain

• LBSL: leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation

• LC: lymphangitis carcinomatosis

• LCA

  • left colic artery

  • left coronary artery

• LCAO: linear combination of atomic orbitals method

• LCCA: left common carotid artery

• LCD: liquid crystal display

• LCH: Langerhans cell histiocytosis

• LCIS: lobular carcinoma in situ

• LCL

  • lateral collateral ligament (of the elbow)

  • lateral collateral ligament (of the knee)

• LCNEC: large cell neuroendocrine carcinoma

• LCRD: localized cystic renal disease

• LCx: left circumflex artery

• LD

  • lactate dehydrogenase

  • learning difficulties

  • lethal dose

• LDH: lactate dehydrogenase

• LDL: low-density lipoprotein

• LDLT: living donor liver transplant

• LE: left eye

• LEAT: long-term epilepsy-associated tumor

• LED: light-emitting diode (display)

• LEOPARD syndrome: lentigines, ECG conduction abnormalities, ocular hyperteloris, pulmonary stenosis, abnormal genitals, retardation of growth, deafness (sensorineural)

• LESA: large endolymphatic sac anomaly

• LETM: longitudinally extensive transverse myelitis

• Leu: leucine

• LF: little finger

• LFC: lateral femoral condyle

• LFT

  • lateral flow test (COVID-19)

  • left ventricular false tendon

• LFTs

  • liver function tests

• LGA

  • large for gestational age

  • left gastric artery

• LGB: laparoscopic gastric banding

• LGE: late gadolinium enhancement

• LGG: low-grade glioma

• LGIB: lower gastrointestinal bleeding

• LGMD: limb-girdle muscular dystrophy

• LGN: lateral geniculate nucleus

• LGNHL: low grade non-Hodgkin lymphoma

• LH: luteinising hormone

• LHA: left hepatic artery

• LHD

  • left hand dominant

  • left hepatic duct

• LHV: left hepatic vein

• LHS

  • left hand side

  • left heart strain

• LIF: left iliac fossa

• LIH: left inguinal hernia

• LIMA: left internal mammary artery

• LIME: local interpretable model-agnostic explanations (AI)

• LIP: lymphoid interstitial pneumonia

• LIQ: lower inner quadrant (breast)

• LI-RADS: liver imaging reporting and data system

• LITA: left internal thoracic artery

• LJT: Lester Jones tube

• LK: left kidney

• LKMP: last known menstrual period

• LKN: last known normal

• LKW: last known well

• LL: lower limb

• LLC: low-level care

• LLE: left lower extremity

• LLETZ: large loop excision of the transformation zone

• LLIF: lateral lumbar interbody fusion

• LLL

  • left lobe of liver

  • left lower limb

  • left lower lobe (of the lung)

• LLP: low lying placenta

• LLQ: left lower quadrant

• LLZ: left lower zone

• LM: lateral meniscus

• Lm: lumen (SI unit of luminous flux)

• LMA: laryngeal mask airway

• LMB: left main bronchus

• LMCA: left main coronary artery

• LMD: leptomeningeal disease

• LMMC: lipomyelomeningocele

• LMO: lateromedial oblique

• LMP: last menstrual period

• LMV: lateral mesencephalic vein

• LMWH: low molecular weight heparin

• LN: lymph node

• LNT: linear no-threshold theory 

• LO: left ovary

• LOA

  • loss of appetite

  • left occipitoanterior

• LOC

  • level of consciousness

  • loss of consciousness

• LOCM: low-osmolar contrast medium

• LOLOL: little old lady off legs

• LOP: left occipitoposterior

• LOQ: lower outer quadrant (breast)

• LOS: late-onset (neonatal) sepsis

• LOT: left occipitotransverse

• LOV: loss of vision

• LOW: loss of weight

• LP

  • line pair

  • lumbar puncture

• LPA

  • lasting power of attorney

  • left pulmonary artery

• Lp(a): lipoprotein a

• LPCVS: long post-COVID vaccination syndrome

• LPD: lymphoproliferative disease

• LPF: low-powered field of view

• LPL: lymphoplasmacytic lymphoma

• LPM: lymphoplasmacyte-rich meningioma

• LP/mm: line pairs/millimeter

• LR: likelihood ratio

• Lr: lawrencium

• LRA: left renal artery

• LRP: laparoscopic radical prostatectomy

• LRRK2: leucine-rich repeat kinase 2

• LRTI

  • lower respiratory tract infection

  • ligament reconstruction and tendon interposition

• LS

  • longitudinal section

  • lumbosacral

• LSCA: left subclavian artery

• LSCC: lateral semicircular canal

• LSCS: lower segment cesarian section

• LSD

  • lysergic acid diethylamide

  • lysosomal storage disease

• LSP: low sperm count

• LSMFT: liposclerosing myxofibrous tumor

• LSTV: lumbosacral transitional vertebra

• LSV

  • left subclavian vein

  • lenticulostriate vasculopathy

• LSW: left-sided weakness

• LT

  • laryngeal tube

  • left

  • leukotriene

• LTBI: latent tuberculosis infection

• LTI: lateral trochlear inclination

• LTx: liver transplant

• Lu: lutetium

• LUCL: lateral ulnar collateral ligament

• LUE: left upper extremity

• LUL

  • left upper limb

  • left upper lobe (of the lung)

• LUO: left ureteric orifice

• LUQ: left upper quadrant

• LURD: living unrelated donor

• LUS: lower uterine segment

• LUSCS: lower uterine segment cesarian section

• LUTS: lower urinary tract symptoms

• LUZ: left upper zone

• LV: left ventricle

• LVA

  • left ventricular aneurysm

  • left vertebral artery

• LVAD: left ventricular assist device

• LVD: left ventricular dilatation

• LVEDD: left ventricular end diastolic diameter

• LVEF: left ventricular ejection fraction

• LVF

  • left ventricular failure

  • left ventricular function

• LVH: left ventricular hypertrophy

• LVI: lymphovascular invasion

• LVMI: left ventricular mass index

• LVO: large vessel occlusion

• LVOT: left ventricular outflow tract 

• LWOT: left without treatment

• LVP: large volume paracentesis

• LVV: large vessel vasculitis

• LWT: left without treatment

• Lx

  • lux (SI unit of illuminance)

  • lymphadenopathy

• Ly: lymphoma

• Lys: lysine

• lytes: electrolytes (e.g. sodium, potassium, chloride, etc.)

• LZ: lower zone