Internal Medicine Abbreviations

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Internal Medicine Alphabet – L

S. No	Abbreviation	Full Form	Short Explanation	Practical Example
L001	LA	Left Atrium	Upper left chamber of the heart.	Enlarged in mitral stenosis.
L002	LABA	Long-Acting Beta-Agonist	Asthma/COPD bronchodilator.	Salmeterol for asthma control.
L003	LAC	Lupus Anticoagulant	Autoantibody causing clotting tendency.	Found in antiphospholipid syndrome.
L004	LAD	Left Anterior Descending (Artery)	Major coronary artery.	LAD occlusion → anterior MI.
L005	LAE	Left Atrial Enlargement	Increase in atrial size on ECG/Echo.	Seen in chronic hypertension.
L006	LAH	Left Atrial Hypertrophy	Thickening of left atrial walls.	Caused by long-standing valve disease.
L007	LAM	Lymphangioleiomyomatosis	Rare lung disease in women.	Causes progressive dyspnea.
L008	LAN	Lymphadenopathy	Enlargement of lymph nodes.	Seen in lymphoma, infection.
L009	LAP	Leukocyte Alkaline Phosphatase	Enzyme marker in hematology.	Elevated in leukemoid reaction.
L010	LAR	Laryngeal Reflex	Protective airway reflex.	Prevents aspiration.
L011	LAS	Left Atrial Size	Measurement in echocardiography.	Index of diastolic dysfunction.
L012	LAT	Lateral	Positioning or radiographic term.	Lateral CXR view.
L013	LBBB	Left Bundle Branch Block	ECG conduction abnormality.	Wide QRS, seen in CHF.
L014	LBP	Low Back Pain	Common musculoskeletal symptom.	Often mechanical or degenerative.
L015	LBR	Leukocyte-to-Basophil Ratio	Inflammatory marker.	Used in hematological studies.
L016	LC	Liver Cirrhosis	Chronic liver scarring.	Caused by alcohol, hepatitis.
L017	LCA	Left Coronary Artery	Major heart vessel.	Supplies left ventricle.
L018	LCAT	Lecithin–Cholesterol Acyltransferase	Enzyme in cholesterol metabolism.	Deficiency → low HDL.
L019	LCC	Left Common Carotid	Supplies blood to brain.	Stenosis leads to stroke.
L020	LCD	Low-Carbohydrate Diet	Diet for obesity/diabetes.	Used in weight loss.
L021	LCH	Langerhans Cell Histiocytosis	Rare clonal disorder.	Causes bone lesions.
L022	LCL	Lateral Collateral Ligament	Knee stabilizing ligament.	Injury common in trauma.
L023	LCM	Lymphocytic Meningitis	Viral meningitis.	Usually self-limiting.
L024	LCN	Lateral Cutaneous Nerve	Nerve supplying thigh sensation.	Injury → meralgia paresthetica.
L025	LCP	Legg-Calvé-Perthes	Childhood hip disorder.	Causes limp in boys.
L026	LCR	Laryngeal Chemo Reflex	Airway reflex to irritants.	Protects against aspiration.
L027	LCS	Lung Cancer Screening	CT scan for high-risk patients.	Recommended for smokers.
L028	LD	Lactate Dehydrogenase	Enzyme elevated in tissue damage.	High in hemolysis, cancer.
L029	LDA	Low-Dose Aspirin	Used in cardiovascular prevention.	Prevents MI/stroke.
L030	LDC	Low-Dose CT	Imaging for early lung cancer detection.	Used in smokers >50 years.
L031	LDL	Low-Density Lipoprotein	“Bad” cholesterol fraction.	Target in statin therapy.
L032	LDM	Left Diaphragmatic Movement	Measured in respiratory exams.	Reduced in phrenic palsy.
L033	LDN	Lymphatic Drainage	Movement of lymph fluid.	Assessed in lymphedema.
L034	LDP	Left Diaphragm Paralysis	Paralysis of diaphragm.	Seen in phrenic nerve injury.
L035	LDR	Low-Dose Radiation	Radiotherapy protocol.	Used in cancer treatment.
L036	LDS	Loeys-Dietz Syndrome	Genetic connective tissue disorder.	Causes aneurysms.
L037	LDT	Lymphocyte Doubling Time	Prognostic marker in leukemia.	Used in CLL monitoring.
L038	LE	Lupus Erythematosus	Autoimmune disease.	Manifests with rash, arthritis.
L039	LEB	Lymphocyte-Enriched Blood	Blood fraction for studies.	Used in immunology.
L040	LEC	Lens Epithelial Cells	Eye epithelial cells.	Role in cataracts.
L041	LED	Light-Emitting Diode	Used in phototherapy.	Treats neonatal jaundice.
L042	LEF	Leflunomide	Immunosuppressive drug.	Used in rheumatoid arthritis.
L043	LEG	Legionella	Bacteria causing pneumonia.	Detected by urine antigen.
L044	LEI	Laryngeal Edema Index	Scale for airway obstruction.	Used in intubation.
L045	LEL	Lower Esophageal Lesion	Gastroenterology finding.	Seen in reflux disease.
L046	LEM	Lower Esophageal Manometry	GI motility test.	Used in achalasia diagnosis.
L047	LEN	Lenalidomide	Immunomodulatory drug.	Used in multiple myeloma.
L048	LEP	Leptin	Hormone regulating satiety.	Deficiency causes obesity.
L049	LES	Lower Esophageal Sphincter	Sphincter controlling reflux.	Weak LES → GERD.
L050	LET	Local Endotracheal Tube	Airway device.	Used in anesthesia.
L051	LF	Liver Function	Physiological activity of liver.	Measured by LFTs.
L052	LFA	Large For Age	Neonatal growth category.	Seen in diabetic mothers.
L053	LFD	Low-Fat Diet	Dietary modification.	Used in hyperlipidemia.
L054	LFE	Left Frontal Epilepsy	Seizures from frontal lobe.	Diagnosed on EEG.
L055	LFF	Left Foot Fracture	Orthopedic injury.	Requires immobilization.
L056	LFG	Left Femoral Graft	Vascular graft.	Used in bypass surgery.
L057	LFH	Left Frontal Hematoma	Brain bleed in frontal lobe.	Seen in head trauma.
L058	LFI	Lung Function Index	Pulmonary measure.	Used in COPD scoring.
L059	LFL	Low Fibrinogen Level	Coagulopathy marker.	Seen in DIC.
L060	LFM	Left Frontal Mass	Tumor in brain.	Diagnosed on MRI

S. No	Abbreviation	Full Form	Short Explanation	Practical Example
L061	LFN	Low-Frequency Neuropathy	Neuropathy detected on low-frequency studies.	Seen in diabetic neuropathy.
L062	LFO	Low-Flow Oxygen	Oxygen delivered at ≤5 L/min.	Nasal cannula therapy.
L063	LFP	Local Field Potential	Electrical brain recording technique.	Used in epilepsy monitoring.
L064	LFQ	Left Femoral Quadrant	Clinical abdominal reference.	Examined in appendicitis.
L065	LFR	Low Fetal Risk	Obstetric risk category.	Determined during prenatal testing.
L066	LFS	Left Frontal Stroke	Ischemic infarct in frontal lobe.	Causes speech disturbance.
L067	LFT	Liver Function Test	Blood panel assessing liver enzymes.	ALT/AST, bilirubin measured.
L068	LFU	Lost to Follow-Up	Patient not returning for care.	Common in long-term studies.
L069	LFW	Low-Fat Weight	Nutritional measure of body mass.	Used in obesity programs.
L070	LGA	Large for Gestational Age	Neonatal growth >90th percentile.	Seen in maternal diabetes.
L071	LGB	Lymphogranuloma Venereum	STI caused by Chlamydia trachomatis.	Causes genital ulcers.
L072	LGC	Low-Grade Cytology	Mild abnormality in Pap smear.	Needs repeat screening.
L073	LGD	Low-Grade Dysplasia	Premalignant tissue change.	Seen in Barrett’s esophagus.
L074	LGF	Left Gastric Fold	Radiological finding.	Assessed in endoscopy.
L075	LGI	Lower Gastrointestinal	Referring to colon/rectum pathology.	LGI bleed common in diverticulosis.
L076	LGIB	Lower Gastrointestinal Bleed	Bleeding distal to ligament of Treitz.	Presents with hematochezia.
L077	LGLL	Large Granular Lymphocytic Leukemia	Chronic lymphoproliferative disorder.	Associated with RA.
L078	LGLS	Left Gastric Lymph Node Station	Node classification in oncology.	Staging of gastric cancer.
L079	LGS	Lennox-Gastaut Syndrome	Severe childhood epilepsy.	Needs multiple antiepileptics.
L080	LGV	Lymphogranuloma Venereum	STD affecting lymphatics.	Painful inguinal lymphadenopathy.
L081	LH	Luteinizing Hormone	Pituitary hormone regulating gonads.	Measured in infertility evaluation.
L082	LHA	Left Hepatic Artery	Artery supplying left liver lobe.	Important in surgery.
L083	LHB	Left Heart Bypass	Temporary circulatory support.	Used in cardiac surgery.
L084	LHC	Left Heart Catheterization	Invasive cardiac test.	Measures LV function.
L085	LHD	Left Heart Disease	Causes pulmonary hypertension.	Includes mitral stenosis.
L086	LHF	Left Heart Failure	LV dysfunction leading to pulmonary edema.	Causes dyspnea, rales.
L087	LHI	Lung Health Index	Composite measure of lung function.	Used in COPD scoring.
L088	LHP	Left Hemiparesis	Weakness of left body side.	Seen in right-sided stroke.
L089	LHR	Lung-to-Head Ratio	Neonatal prognostic index.	Used in diaphragmatic hernia.
L090	LHS	Lown-Ganong-Levine Syndrome	Pre-excitation cardiac disorder.	Causes supraventricular tachycardia.
L091	LHT	Liver Hypertension Test	Test for portal hypertension.	Assesses cirrhosis severity.
L092	LHV	Left Hepatic Vein	Drains left liver lobe.	Identified in liver imaging.
L093	LI	Lithium	Psychiatric medication.	Used in bipolar disorder.
L094	LIA	Local Immunoassay	Diagnostic antibody test.	Detects viral antigens.
L095	LIC	Low-Income Country	Epidemiological classification.	Used in global health studies.
L096	LID	Lidocaine	Local anesthetic & antiarrhythmic.	Used in VTach.
L097	LIF	Leukemia Inhibitory Factor	Cytokine involved in cell signaling.	Studied in oncology.
L098	LIG	Ligament	Connective tissue structure.	Torn ACL in athletes.
L099	LIM	Limb Ischemia	Reduced blood supply to limb.	Emergency in vascular disease.
L100	LIN	Linezolid	Oxazolidinone antibiotic.	Used in MRSA infection.
L101	LIP	Lipase	Enzyme breaking down fat.	Elevated in pancreatitis.
L102	LIS	Lateral Internal Sphincterotomy	Surgery for anal fissures.	Improves healing.
L103	LIT	Laser-Induced Thermotherapy	Cancer ablation technique.	Used in liver tumors.
L104	LIV	Liver	Vital organ for metabolism.	Assessed by biopsy.
L105	LKA	Locked Knee Arthritis	Severe osteoarthritis of knee.	Requires replacement.
L106	LKB	LKB1 Gene	Tumor suppressor.	Mutated in Peutz-Jeghers.
L107	LKC	Large-Kernel Cell	Pathology term.	Seen in lymphoma.
L108	LKG	Lower Kidney Graft	Surgical transplant position.	Used in renal transplant.
L109	LKN	Last Known Normal	Stroke onset timing reference.	Used in thrombolysis decisions.
L110	LKO	Liver Knockout	Genetic study model.	Used in hepatology research.
L111	LL	Lower Lobe	Anatomical lung region.	Right LL pneumonia on CXR.
L112	LLA	Left Lower Abdomen	Abdominal quadrant.	Pain in diverticulitis.
L113	LLC	Left Lower Chest	Thoracic region.	Examined in trauma.
L114	LLD	Left Lateral Decubitus	Position for exam or imaging.	Used in echocardiography.
L115	LLE	Left Lower Extremity	Clinical shorthand.	DVT in LLE.
L116	LLF	Left Lower Femur	Orthopedic reference.	Fracture in trauma.
L117	LLL	Left Lower Lobe	Lung lobe.	Infected in aspiration pneumonia.
L118	LLM	Left Lower Molar	Dental reference.	Extracted in infection.
L119	LLO	Left Lower Orbit	Ophthalmology region.	Trauma to orbital floor.
L120	LLP	Left Lower Pole	Kidney reference.	Biopsy site in nephrology.
L121	LLR	Left Lower Ribs	Chest exam site.	Tender in trauma.
L122	LLS	Left Lower Segment	Lung segment.	Seen on HRCT.
L123	LLT	Long-Lasting Therapy	Extended treatment duration.	HIV lifelong ART.
L124	LLV	Low-Level Viremia	Small detectable viral load.	Monitored in HIV therapy.
L125	LM	Left Main (Coronary Artery)	Major coronary artery.	LM stenosis → severe angina.
L126	LMA	Laryngeal Mask Airway	Airway device.	Used in anesthesia.
L127	LMC	Local Medical Center	Healthcare institution.	Patient referred to LMC.
L128	LMD	Localized Muscular Dystrophy	Muscle-wasting disease.	Duchenne subtype.
L129	LME	Local Medical Examiner	Forensic physician.	Declares cause of death.
L130	LMF	Low-Molecular-Weight Fraction	Drug classification.	Used in heparins.
L131	LMG	Left Middle Gyrus	Brain structure.	Seen in stroke imaging.
L132	LMI	Left Mainstem Intubation	Wrong tube placement.	Leads to right lung collapse.
L133	LML	Left Middle Lobe	Lung segment.	Site for pneumonia.
L134	LMM	Lymphoplasmacytic Myeloma	Plasma cell neoplasm.	Produces IgM.
L135	LMN	Lower Motor Neuron	Nervous system component.	ALS affects LMNs.
L136	LMO	Local Medical Officer	Primary care doctor.	Manages chronic illness.
L137	LMP	Last Menstrual Period	Gynecological reference.	Used for pregnancy dating.
L138	LMR	Lymphocyte-to-Monocyte Ratio	Hematology index.	Prognostic marker in cancer.
L139	LMS	Leiomyosarcoma	Smooth muscle tumor.	Can occur in uterus.
L140	LMT	Limbic Memory Test	Neuropsychological test.	Used in dementia evaluation.
L141	LMV	Low-Molecular-Weight Vaccine	Immunology concept.	Studied in cancer vaccines.
L142	LN	Lymph Node	Lymphatic tissue.	Enlarged in infection.
L143	LNA	Lymph Node Aspiration	Diagnostic test.	Used in TB lymphadenitis.
L144	LNC	Lung Nodule Clinic	Specialized service.	Evaluates incidental nodules.
L145	LND	Lymph Node Dissection	Surgical removal of nodes.	Done in cancer staging.
L146	LNE	Lymph Node Enlargement	Enlargement of nodes.	Seen in lymphoma.
L147	LNF	Laparoscopic Nissen Fundoplication	GERD surgery.	Corrects reflux.
L148	LNG	Levonorgestrel	Progestin contraceptive.	Used in emergency contraception.
L149	LNH	Lymph Node Hyperplasia	Reactive node change.	Seen in infection.
L150	LNI	Lymph Node Involvement	Cancer staging term.	Present in breast cancer.
L151	LNL	Lymph Node Level	Classification system.	Used in head & neck cancer.
L152	LNM	Lymph Node Metastasis	Cancer spread to nodes.	Common in GI cancers.
L153	LNP	Licensed Nurse Practitioner	Advanced practice nurse.	Provides primary care.
L154	LNR	Lymph Node Ratio	Prognostic cancer marker.	Used in GI oncology.
L155	LNS	Lymph Node Sampling	Biopsy for diagnosis.	Done in lung cancer.
L156	LNT	Linear No-Threshold (Model)	Radiation risk model.	Used in oncology safety.
L157	LNV	Low Nasal Volume	ENT measure.	Used in sinusitis studies.
L158	LOA	Left Occipito-Anterior	Fetal position in labor.	Common delivery position.
L159	LOC	Level of Consciousness	Neurological assessment.	GCS score evaluation.
L160	LOE	Loss of Elasticity	Age-related tissue change.	Seen in skin.
L161	LOH	Loss of Heterozygosity	Genetic alteration.	Studied in cancer.
L162	LOM	Limitation of Motion	Orthopedic finding.	Seen in arthritis.
L163	LOP	Left Occipito-Posterior	Fetal malposition in labor.	Causes prolonged delivery.
L164	LOR	Loss of Resistance	Technique for epidural anesthesia.	Identifies epidural space.
L165	LOS	Length of Stay	Hospital duration.	Average LOS metric.
L166	LOT	Left Occipito-Transverse	Fetal malposition.	Managed in obstetrics.
L167	LOV	Left Ovarian Vein	Vein draining ovary.	Involved in thrombosis.
L168	LP	Lumbar Puncture	Procedure to obtain CSF.	Used in meningitis diagnosis.
L169	LPA	Left Pulmonary Artery	Supplies left lung.	Blocked in pulmonary embolism.
L170	LPB	Lumbar Plexus Block	Anesthesia technique.	Used in hip surgery.
L171	LPC	Left Pleural Cavity	Thoracic space.	Site of effusion.
L172	LPD	Left Parietal Deficit	Cognitive disorder.	Seen in stroke.
L173	LPE	Local Pulmonary Embolism	Clot in pulmonary artery.	Diagnosed by CTPA.
L174	LPI	Laser Peripheral Iridotomy	Ophthalmic procedure.	Used in angle-closure glaucoma.
L175	LPL	Lipoprotein Lipase	Enzyme metabolizing triglycerides.	Deficiency causes hyperlipidemia.
L176	LPM	Left Psoas Muscle	Retroperitoneal structure.	Abscess occurs in TB.
L177	LPN	Licensed Practical Nurse	Nursing professional.	Provides bedside care.
L178	LPO	Left Posterior Oblique	Radiographic position.	Used in chest imaging.
L179	LPP	Lichen Planus Pigmentosus	Dermatological condition.	Hyperpigmented lesions.
L180	LPR	Laryngopharyngeal Reflux	Reflux reaching throat.	Causes chronic cough.
L181	LPS	Lipopolysaccharide	Bacterial endotoxin.	Triggers sepsis.
L182	LPT	Late Preterm	Infant born 34–36 weeks.	Higher morbidity risk.
L183	LPV	Lopinavir	HIV protease inhibitor.	Used in ART regimens.
L184	LQ	Lower Quadrant	Abdominal exam region.	RLQ pain in appendicitis.
L185	LQTS	Long QT Syndrome	Cardiac arrhythmia disorder.	Causes sudden death.
L186	LR	Lactated Ringer’s	IV fluid.	Used in resuscitation.
L187	LRA	Left Renal Artery	Supplies kidney.	Stenosis → hypertension.
L188	LRD	Living Related Donor	Transplant terminology.	Kidney donation.
L189	LRF	Local Recurrence-Free (Survival)	Oncology endpoint.	Used in cancer follow-up.
L190	LRI	Limbal Relaxing Incision	Ophthalmic procedure.	Corrects astigmatism.
L191	LRL	Lower Rate Limit	Pacemaker setting.	Determines minimum HR.
L192	LRM	Left Rectus Muscle	Extraocular muscle.	Paralysis affects eye movement.
L193	LRN	Local Regional Node	Cancer staging term.	Seen in breast cancer.
L194	LRR	Locoregional Recurrence	Cancer returning near site.	Breast cancer recurrence.
L195	LRT	Lower Respiratory Tract	Trachea, bronchi, lungs.	Site of pneumonia.
L196	LRV	Left Renal Vein	Vein draining kidney.	Nutcracker syndrome.
L197	LS	Lumbosacral	Spine region.	Common site of disc herniation.
L198	LSA	Left Subclavian Artery	Supplies left arm.	Trauma → bleeding.
L199	LSB	Left Sternal Border	Auscultation site.	Murmurs heard in HOCM.
L200	LSC	Laparoscopic Cholecystectomy	Minimally invasive gallbladder removal.	Treatment for gallstones.