Internal Medicine Initialisms

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Internal Medicine Alphabet – A

S. No	Initialism	Full Form	Short Explanation	Practical Example
A001	ABG	Arterial Blood Gas	Test measuring oxygen, carbon dioxide, and pH in arterial blood	Used in ICU to assess respiratory failure
A002	ACE	Angiotensin-Converting Enzyme	Enzyme converting angiotensin I to II, regulating BP	ACE inhibitors used in hypertension
A003	ACE-I	Angiotensin-Converting Enzyme Inhibitor	Class of drugs lowering BP by blocking ACE	Lisinopril in heart failure
A004	ACLS	Advanced Cardiac Life Support	Protocol for managing cardiac arrest and emergencies	Used in ER resuscitation
A005	ACTH	Adrenocorticotropic Hormone	Hormone stimulating cortisol production	Measured in adrenal insufficiency
A006	ADH	Antidiuretic Hormone	Hormone regulating water retention in kidneys	Deficient in diabetes insipidus
A007	AED	Automated External Defibrillator	Portable device analyzing rhythm and delivering shocks	Public use in cardiac arrest
A008	AF	Atrial Fibrillation	Irregular rapid heart rhythm	Anticoagulation given to prevent stroke
A009	AFP	Alpha-Fetoprotein	Tumor marker, also elevated in liver disease	Monitored in hepatocellular carcinoma
A010	AI	Aortic Insufficiency	Valve disease causing backflow into LV	Diagnosed via echocardiography
A011	AIDS	Acquired Immunodeficiency Syndrome	Advanced HIV infection with opportunistic infections	Kaposi’s sarcoma in AIDS patient
A012	AKI	Acute Kidney Injury	Sudden decline in renal function	Seen after sepsis or nephrotoxic drugs
A013	ALD	Alcoholic Liver Disease	Spectrum of liver damage from alcohol	Cirrhosis in chronic alcohol abuse
A014	ALP	Alkaline Phosphatase	Enzyme elevated in liver or bone disorders	Raised in cholestatic liver disease
A015	ALT	Alanine Aminotransferase	Liver enzyme, marker of hepatocellular injury	Elevated in hepatitis
A016	AMA	Anti-Mitochondrial Antibody	Autoantibody specific for primary biliary cholangitis	Positive in middle-aged female with cholestasis
A017	AMI	Acute Myocardial Infarction	Heart attack due to blocked coronary artery	Diagnosed with troponins + ECG
A018	ANA	Antinuclear Antibody	Autoantibody seen in autoimmune diseases	Positive in systemic lupus erythematosus
A019	ANCA	Anti-Neutrophil Cytoplasmic Antibody	Marker for vasculitis	c-ANCA positive in granulomatosis with polyangiitis
A020	ANS	Autonomic Nervous System	Controls involuntary functions	Dysfunction in diabetic neuropathy
A021	aPTT	Activated Partial Thromboplastin Time	Test for intrinsic clotting pathway	Monitored in heparin therapy
A022	AR	Aortic Regurgitation	Valve disease with backflow from aorta to LV	Murmur detected during auscultation
A023	ARDS	Acute Respiratory Distress Syndrome	Severe lung injury causing hypoxemia	Seen in sepsis or trauma
A024	ARF	Acute Renal Failure	Sudden renal dysfunction, old term for AKI	Oliguria after shock
A025	AS	Aortic Stenosis	Narrowed aortic valve obstructing flow	Elderly patient with syncope + murmur
A026	ASA	Acetylsalicylic Acid	Aspirin, antiplatelet & analgesic drug	Given in acute coronary syndrome
A027	AST	Aspartate Aminotransferase	Liver enzyme, less specific than ALT	Elevated in alcoholic liver disease
A028	ATN	Acute Tubular Necrosis	Common cause of intrinsic AKI	Occurs after ischemia or nephrotoxic drugs
A029	AV	Atrioventricular	Refers to heart’s conduction system	AV block seen in ECG
A030	AVNRT	Atrioventricular Nodal Reentrant Tachycardia	Common supraventricular tachycardia	Palpitations in young adults
A031	AVRT	Atrioventricular Reentrant Tachycardia	Tachycardia via accessory pathway	Seen in Wolff-Parkinson-White syndrome
A032	AVF	Arteriovenous Fistula	Abnormal artery-vein connection	Dialysis access in CKD
A033	AVM	Arteriovenous Malformation	Abnormal tangle of vessels	Can cause brain hemorrhage
A034	AVR	Aortic Valve Replacement	Surgical treatment for severe aortic valve disease	Indicated in severe aortic stenosis
A035	ABI	Ankle-Brachial Index	Test comparing BP in ankle vs arm	Used to diagnose peripheral artery disease
A036	ACR	Albumin-to-Creatinine Ratio	Urine test for microalbuminuria	Early marker in diabetic nephropathy
A037	AATD	Alpha-1 Antitrypsin Deficiency	Genetic cause of emphysema & liver disease	Young patient with COPD & liver issues
A038	AAA	Abdominal Aortic Aneurysm	Abnormal dilation of abdominal aorta	Screened by ultrasound in elderly males
A039	ACS	Acute Coronary Syndrome	Spectrum: unstable angina, NSTEMI, STEMI	Chest pain + troponins + ECG changes
A040	ACT	Activated Clotting Time	Test to monitor anticoagulation during procedures	Measured during cardiac catheterization
A041	AGA	Appropriate for Gestational Age	Neonatal growth classification	Used in obstetric medicine
A042	AIHA	Autoimmune Hemolytic Anemia	Autoantibodies destroy RBCs	Positive Coombs test
A043	ALCL	Anaplastic Large Cell Lymphoma	Type of non-Hodgkin lymphoma	Diagnosed via lymph node biopsy
A044	AML	Acute Myeloid Leukemia	Aggressive blood cancer	Bone marrow biopsy for diagnosis
A045	ALL	Acute Lymphoblastic Leukemia	Childhood leukemia	Treated with chemotherapy
A046	ANC	Absolute Neutrophil Count	Important in infection risk assessment	Neutropenia in chemotherapy patients
A047	APA	Antiphospholipid Antibody	Associated with clotting disorders	Recurrent miscarriages in APS
A048	APS	Antiphospholipid Syndrome	Autoimmune clotting disorder	DVT + recurrent pregnancy loss
A049	ARPKD	Autosomal Recessive Polycystic Kidney Disease	Rare genetic kidney disorder	Seen in infants with enlarged kidneys
A050	ADPKD	Autosomal Dominant Polycystic Kidney Disease	Common inherited kidney disease	Bilateral kidney cysts in adults

S. No	Initialism	Full Form	Short Explanation	Practical Example
A051	AFB	Acid-Fast Bacillus	Bacteria that retain special stain (e.g., Mycobacteria)	Sputum AFB stain for TB diagnosis
A052	AFE	Amniotic Fluid Embolism	Rare obstetric emergency	Sudden collapse during delivery
A053	AFI	Amniotic Fluid Index	Ultrasound measurement of amniotic fluid	Monitored in high-risk pregnancies
A054	AFN	Acute Febrile Neutrophilia	High WBC count with fever	Seen in severe bacterial infection
A055	AFP-L3	Alpha-Fetoprotein-L3	Tumor marker fraction for liver cancer	Monitored in hepatocellular carcinoma
A056	AG	Anion Gap	Difference between measured cations and anions	Used in metabolic acidosis diagnosis
A057	AGA	Anti-Gliadin Antibody	Marker for celiac disease	Positive in gluten intolerance
A058	AGR	Albumin-Globulin Ratio	Ratio used in liver and kidney disease	Low in cirrhosis
A059	AI	Artificial Insemination	Infertility treatment technique	Used in reproductive medicine
A060	AIDP	Acute Inflammatory Demyelinating Polyneuropathy	Common form of Guillain–Barré syndrome	Rapid-onset paralysis after infection
A061	AIP	Acute Intermittent Porphyria	Rare metabolic disorder	Abdominal pain + neuropathy
A062	AIRDS	Acute Interstitial Renal Disease Syndrome	Rare form of kidney inflammation	Seen with drug-induced nephritis
A063	AJR	American Journal of Roentgenology	Renowned radiology journal	Reference for imaging cases
A064	AKT	Anti-Koch Therapy	Treatment for tuberculosis	Isoniazid, rifampicin-based regimen
A065	ALAS	Acute Limb Arterial Syndrome	Sudden loss of blood flow to limb	Emergency revascularization needed
A066	ALD	Aldosterone	Hormone regulating sodium & potassium balance	Excess in Conn’s syndrome
A067	ALI	Acute Lung Injury	Non-cardiogenic pulmonary edema	Precursor to ARDS
A068	ALK	Anaplastic Lymphoma Kinase	Oncogene in lung cancer	Targeted by ALK inhibitors
A069	ALND	Axillary Lymph Node Dissection	Surgical procedure in breast cancer	Staging for malignancy
A070	AMLA	Acute Myeloblastic Leukemia with maturation	Subtype of AML	Classified via cytogenetics
A071	AMR	Acute Mitral Regurgitation	Sudden failure of mitral valve	Post-MI papillary muscle rupture
A072	AMT	Anti-Malarial Therapy	Medications against malaria	Artemisinin-based therapy
A073	ANA-IIF	ANA by Indirect Immunofluorescence	Sensitive test for autoimmune disease	Used in lupus screening
A074	ANCOVA	Analysis of Covariance	Statistical tool in clinical trials	Used in drug efficacy research
A075	ANF	Atrial Natriuretic Factor	Hormone reducing blood pressure	Elevated in heart failure
A076	ANP	Atrial Natriuretic Peptide	Same as ANF, regulates BP & volume	Measured in cardiac disease
A077	ANSD	Auditory Neuropathy Spectrum Disorder	Hearing disorder affecting signal transmission	Diagnosed with audiometry
A078	AOM	Acute Otitis Media	Middle ear infection	Common in children with fever
A079	AP	Anteroposterior	Radiographic view terminology	AP chest X-ray
A080	APA	American Psychiatric Association	Professional body for psychiatrists	Publishes DSM classification
A081	APC	Activated Protein C	Anticoagulant protein in body	Deficiency causes thrombosis
A082	APD	Automated Peritoneal Dialysis	Home-based dialysis method	CKD patients on home therapy
A083	APGAR	Appearance, Pulse, Grimace, Activity, Respiration	Newborn assessment score	Used immediately after delivery
A084	APE	Acute Pulmonary Embolism	Blockage of pulmonary artery	Sudden dyspnea + chest pain
A085	APL	Acute Promyelocytic Leukemia	Subtype of AML, responds to ATRA	Emergency due to coagulopathy
A086	APLA	Antiphospholipid Antibody	Causes clotting and pregnancy loss	Tested in APS workup
A087	APM	Anterior Pituitary Macroadenoma	Large tumor in pituitary gland	Causes vision loss and hormone imbalance
A088	APOE	Apolipoprotein E	Gene associated with Alzheimer’s disease	APOE4 increases risk
A089	APRI	AST-to-Platelet Ratio Index	Non-invasive fibrosis score	Used in hepatitis C
A090	APSGN	Acute Post-Streptococcal Glomerulonephritis	Kidney disease after strep infection	Hematuria + edema in child
A091	APV	Assisted Positive Ventilation	Mode of ventilatory support	Used in respiratory failure
A092	AR	Allergic Rhinitis	Inflammatory nasal allergy	Treated with antihistamines
A093	ARC	AIDS-Related Complex	Early stage of HIV	Weight loss, fever, infections
A094	ARDSnet	Acute Respiratory Distress Network	Trial group for ARDS protocols	Developed lung-protective ventilation
A095	ARI	Acute Respiratory Infection	Broad term for chest infections	Pneumonia, bronchitis
A096	ARMD	Age-Related Macular Degeneration	Leading cause of blindness	Elderly with central vision loss
A097	ARN	Acute Renal Necrosis	Severe form of AKI	Causes oliguria and uremia
A098	ARR	Aldosterone Renin Ratio	Screening test for hyperaldosteronism	Used in resistant hypertension
A099	ART	Antiretroviral Therapy	Drugs for HIV infection	HAART regimen in AIDS
A100	ARVC	Arrhythmogenic Right Ventricular Cardiomyopathy	Genetic cardiomyopathy	Young athlete with sudden death
A101	ASC	Atypical Squamous Cells	Abnormal Pap smear result	ASC-US in cervical cytology
A102	ASD	Atrial Septal Defect	Congenital heart disease	Fixed split S2 on auscultation
A103	ASH	American Society of Hematology	Professional society for hematology	Publishes “Blood” journal
A104	ASHD	Arteriosclerotic Heart Disease	Atherosclerosis of coronary arteries	Cause of angina and MI
A105	ASO	Anti-Streptolysin O	Antibody against streptococcus	Elevated in rheumatic fever
A106	ASR	Acute Stress Reaction	Psychological response to trauma	Anxiety after accident
A107	ASTH	Asthma	Chronic airway inflammatory disease	Wheezing + reversible obstruction
A108	ASVD	Arteriosclerotic Vascular Disease	Systemic atherosclerosis	PAD, CAD, CVD combined
A109	AT	Adenine-Thymine	Base pair in DNA	Genetic mutation studies
A110	ATD	Anti-Thyroid Drugs	Medications for hyperthyroidism	Methimazole, PTU
A111	ATLS	Advanced Trauma Life Support	Emergency protocol for trauma care	Used in ER resuscitation
A112	ATP	Adenosine Triphosphate	Cellular energy molecule	ATP depletion in ischemia
A113	ATR	Atrial Tachycardia	Arrhythmia arising from atria	Palpitations on ECG
A114	ATS	American Thoracic Society	Professional body for lung medicine	Issues COPD guidelines
A115	ATSA	Acute Thrombotic Stroke Attack	Sudden stroke due to clot	Treated with thrombolysis
A116	ATV	Atazanavir	Protease inhibitor for HIV	Used in ART regimen
A117	AUD	Alcohol Use Disorder	Chronic problematic drinking	Screened via CAGE questionnaire
A118	AUS	Atypical Urothelial Cells	Urine cytology abnormality	Investigated for bladder cancer
A119	AV	Atrioventricular Node	Conduction relay between atria & ventricles	AV nodal delay on ECG
A120	AVB	Atrioventricular Block	Conduction block in heart	First-degree AV block on ECG
A121	AVC	Atrioventricular Canal Defect	Congenital heart disease	Associated with Down syndrome
A122	AVG	Arteriovenous Graft	Vascular access for dialysis	Used in ESRD patients
A123	AVI	Aortic Valve Insufficiency	Aortic regurgitation synonym	Murmur in diastole
A124	AVP	Arginine Vasopressin	Another name for ADH	Given in shock management
A125	AVPU	Alert, Voice, Pain, Unresponsive	Consciousness assessment scale	Used in emergency trauma
A126	AVSD	Atrioventricular Septal Defect	Congenital heart disease	Seen in trisomy 21
A127	AWMI	Anterior Wall Myocardial Infarction	MI affecting anterior LV wall	ECG shows ST elevation in V1-V4
A128	AZA	Azathioprine	Immunosuppressant drug	Used in SLE, IBD
A129	AZT	Azidothymidine (Zidovudine)	Nucleoside reverse transcriptase inhibitor	Early HIV treatment
A130	AAD	Antibiotic-Associated Diarrhea	Side effect of antibiotics	C. difficile colitis
A131	AAF	African American Female	Demographic shorthand in studies	Used in clinical trial reporting
A132	AAH	Atypical Adenomatous Hyperplasia	Pre-cancerous lung lesion	Found in pathology
A133	AAL	Anterior Axillary Line	Surface landmark in chest	Used in thoracentesis
A134	AAP	American Academy of Pediatrics	Pediatric professional body	Issues child health guidelines
A135	AAR	Average Annual Rate	Epidemiological measure	Used in incidence reporting
A136	AAS	Acute Abdomen Syndrome	Emergency abdominal condition	Appendicitis, perforation
A137	AAT	Alpha-1 Antitrypsin	Protein protecting lungs from elastase	Deficiency → emphysema
A138	AB	Antibiotics	Drugs against bacteria	Given in pneumonia
A139	ABC	Airway, Breathing, Circulation	Resuscitation basics	Used in BLS & ACLS
A140	ABVD	Adriamycin, Bleomycin, Vinblastine, Dacarbazine	Chemo regimen for Hodgkin lymphoma	First-line treatment protocol
A141	AC	Acromioclavicular	Joint of shoulder	AC joint dislocation
A142	ACA	Anterior Cerebral Artery	Brain artery supplying frontal lobe	Stroke in ACA territory
A143	ACC	American College of Cardiology	Cardiology professional society	Publishes ACC/AHA guidelines
A144	ACD	Anemia of Chronic Disease	Hypoproliferative anemia	Seen in CKD, infections
A145	ACE2	Angiotensin-Converting Enzyme 2	Receptor for SARS-CoV-2 virus	Target of COVID-19 entry
A146	ACH	Acetylcholine	Neurotransmitter in CNS & PNS	Blocked in myasthenia gravis
A147	ACL	Anterior Cruciate Ligament	Knee stabilizing ligament	ACL tear in athletes
A148	ACM	Acute Coronary Mortality	Death due to heart disease	Epidemiology measure
A149	ACOS	Asthma-COPD Overlap Syndrome	Chronic airway disease overlap	Mixed features of asthma & COPD
A150	ACP	American College of Physicians	Internal medicine body	Publishes Annals of IM
A151	ACRL	American College of Radiology and Laboratory	Diagnostic professional body	Standardizes imaging protocols
A152	ACTA	Activated Clotting Time Assay	Test for coagulation	Used in cardiac surgery
A153	ACTG	AIDS Clinical Trials Group	HIV research group	Designs ART trials
A154	ACV	Acute Cerebrovascular Accident	Another name for stroke	Sudden hemiplegia
A155	AD	Alzheimer’s Disease	Neurodegenerative dementia	Memory loss in elderly
A156	ADA	American Diabetes Association	Authority on diabetes care	Publishes ADA guidelines
A157	ADD	Attention Deficit Disorder	Neurobehavioral condition	Child with inattention
A158	ADH	Alcohol Dehydrogenase	Enzyme metabolizing ethanol	Deficiency → flushing with alcohol
A159	ADL	Activities of Daily Living	Functional independence measure	Used in rehab medicine
A160	ADP	Adenosine Diphosphate	Platelet activator molecule	Target of clopidogrel
A161	ADR	Adverse Drug Reaction	Harmful effect of drug	Rash after penicillin
A162	ADS	Alzheimer’s Dementia Syndrome	Advanced stage of Alzheimer’s	Severe cognitive decline
A163	AEB	As Evidenced By	Documentation phrase in nursing	Used in care plans
A164	AEDF	Absent End-Diastolic Flow	Doppler finding in fetus	Suggests IUGR
A165	AERD	Aspirin-Exacerbated Respiratory Disease	Asthma, nasal polyps, aspirin sensitivity	Seen in Samter’s triad
A166	AF	Atrial Flutter	Organized atrial tachyarrhythmia	ECG saw-tooth pattern
A167	AFM	Acute Flaccid Myelitis	Rare neurological disease	Limb weakness in children
A168	AFO	Ankle Foot Orthosis	Support device for gait	Used in foot drop
A169	AFP	Acute Flaccid Paralysis	Sudden limb paralysis	Poliomyelitis surveillance
A170	AFS	Acid-Fast Stain	Diagnostic TB stain	Ziehl-Neelsen technique
A171	AGC	Atypical Glandular Cells	Abnormal Pap smear result	Colposcopy recommended
A172	AGN	Acute Glomerulonephritis	Kidney inflammation	Hematuria, edema, hypertension
A173	AHA	American Heart Association	Cardiology guideline authority	Publishes AHA guidelines
A174	AHF	Acute Heart Failure	Sudden cardiac decompensation	Pulmonary edema in ER
A175	AHP	Acute Hepatic Porphyria	Group of porphyrias	Neurovisceral attacks
A176	AHRE	Atrial High-Rate Episodes	Device-detected atrial tachyarrhythmias	Seen in pacemaker monitoring
A177	AIIMS	All India Institute of Medical Sciences	Premier medical institute in India	Known for advanced IM research
A178	AIM	Acute Inflammatory Myopathy	Muscle inflammation	Proximal muscle weakness
A179	AION	Anterior Ischemic Optic Neuropathy	Sudden optic nerve ischemia	Sudden painless vision loss
A180	AIR	Acute Interstitial Nephritis	Drug-induced renal inflammation	Rash + eosinophilia
A181	AK	Actinic Keratosis	Precancerous skin lesion	Sun-exposed elderly patient
A182	ALI	Acute Leukemia Index	Diagnostic scoring system	Used in hematology
A183	ALMS	Alström Syndrome	Rare genetic multisystem disorder	Obesity + cardiomyopathy
A184	ALT-PEP	Alanine Aminotransferase Peptide	Biomarker in liver disease	Used in lab studies
A185	AMAG	Autoimmune Metaplastic Atrophic Gastritis	Precursor to gastric cancer	B12 deficiency anemia
A186	AMH	Anti-Müllerian Hormone	Ovarian reserve marker	Used in fertility testing
A187	AMI	Acute Mesenteric Ischemia	Sudden loss of intestinal blood supply	Severe abdominal pain
A188	AMPK	AMP-Activated Protein Kinase	Cellular energy sensor	Target in diabetes therapy
A189	AMS	Altered Mental Status	Clinical presentation in ER	Seen in hypoglycemia
A190	ANA	Anorexia Nervosa	Eating disorder	Teenager with weight loss
A191	ANG II	Angiotensin II	Potent vasoconstrictor	Target of ARBs
A192	ANS	Anaphylactic Shock	Severe allergic reaction	Treated with epinephrine
A193	AOCD	Anemia of Chronic Disease	Hypoproliferative anemia	Seen in RA, TB
A194	AOMI	Acute Occlusive Mesenteric Ischemia	Intestinal infarction	Abdominal pain out of proportion
A195	APACHE	Acute Physiology and Chronic Health Evaluation	ICU severity scoring system	APACHE II score in sepsis
A196	APOA1	Apolipoprotein A1	HDL protein	Measured in lipid profile
A197	APP	Amyloid Precursor Protein	Protein involved in Alzheimer’s	Target in dementia research
A198	APRV	Airway Pressure Release Ventilation	Mode of mechanical ventilation	Used in ARDS
A199	ARB	Angiotensin Receptor Blocker	Antihypertensive drug class	Losartan for HTN
A200	ATG	Anti-Thymocyte Globulin	Immunosuppressive antibody	Used in aplastic anemia