| I | impression |
| I | Iodine |
| I | Intermediate |
| I | incontinent |
| I | independent |
| I | initial |
| I | iris |
| I | immune |
| I&A | irrigation and aspiration |
| I&D | incision and debridement |
| I&D | incision and drainage |
| I&E | ingress and egress |
| I&E | internal and external |
| I&J | insight and judgment |
| I&R | insertion and removal |
| I&S | intact and symmetrical |
| I/DD | intellectual and developmental disabilities |
| I/P | iris/pupil |
| I:E ratio | inspiratory to expiratory time ratio |
| IA | intra arterial |
| IA | immune adherence |
| IA | infantile autism |
| IA | intermittent auscultation |
| IA | intra-amniotic |
| IA | intra-arterial |
| IA | intra-articular |
| IAA | ileoanal anastomosis |
| IAA | insulin autoantibodies |
| IAA | interrupted aortic arch |
| IAAA | inflammatory abdominal aortic aneurysms |
| IAAT | intrabdominal adipose tissue |
| IAB | incomplete abortion |
| IAB | induced abortion |
| IAC | internal auditory canal |
| IAD | intra-aortic counterpulsation |
| IAD | implantable atrial defibrillator |
| IAF | intra-abdominal fat |
| IAG | International Association of Gerontologists |
| IAG | indolyl-3-acryloylglycine |
| IAHA | immune adherence hemagglutination |
| IAI | intra-abdominal infection |
| IAI | intra-abdominal injury |
| IALD | instrumental activities of daily living |
| IAM | internal auditory meatus |
| IAN | inferior alveolar nerve |
| IAO | immediately after onset |
| IAO | intermittent aortic occlusion |
| IAP | intra-abdominal pressure |
| IAQ | indoor air quality |
| IAS | idiopathic ankylosing spondylitis |
| IAT | immunoaugmentive therapy |
| IAT | indirect antiglobulin test |
| IAV | intrinsic atrioventricular conduction |
| IB | ileal bypass |
| IB | insulin-receptor binding test |
| IB | isolation bed |
| IBAM | idiopathic bile acid malabsorption |
| IBBB | intra-blood-brain barrier |
| IBC | invasive bladder cancer |
| IBC | iron binding capacity |
| IBD | Inflammatory Bowel Disease |
| IBD | infectious bursal disease |
| IBE | individual bioequivalence |
| IBE | intrahepatic biliary epithelial |
| IBG | iliac bone graft |
| IBI | intermittent bladder irrigation |
| IBIA | Interntional Brain Injury Association |
| IBIA | interferon beta-Ia |
| IBILI | indirect bilirubin |
| IBM | inclusion body myositis |
| IBM | ideal body mass (index of body mass) |
| IBNR | incurred but not reported |
| IBP | ibuprofen |
| IBR | immediate breast reconstruction |
| IBS | irritable bowel syndrome |
| IBT | ink blot test |
| IBT | immune-based therapy |
| IBU | ibuprofen |
| IBU | inflammatory back pain |
| IBU | invasive blood pressure |
| IBU | iron binding protein |
| IBW | ideal body weight |
| IC | inspiratory capacity |
| IC | immune complex |
| IC | inorganic carbon |
| IC | iliac crest |
| IC | intensive care |
| IC | incomplete |
| IC | intermediate care |
| IC | interstitial changes |
| IC | intracerebral |
| IC | irritable colon |
| IC | between meals |
| ICA | internal carotid artery |
| ICA | intermediate care area |
| ICA | ileocolic anastomosis |
| ICA | intracranial abscess |
| ICa | calcium, ionized |
| ICAD | internal carotid artery dissection |
| ICAD | intracranial atherosclerotic disease |
| ICAM | intracellular adhesion molecule |
| ICAO | internal carotid artery occlusion |
| ICAS | intermediate coronary artery syndrome |
| ICAT | isotope-coded affinity tagging |
| ICAT | infant cardiac arrest tray |
| ICB | intracranial bleeding |
| ICC | intensive coronary care |
| ICC | invasive cervical cancer |
| ICC | idiopathic chronic cough |
| ICC | immunocytochemistry |
| ICD | implantable cardioverter defibrillator |
| ICD | informed consent document |
| ICD | instantaneous cardiac death |
| ICD | irritant contact dermatitis |
| ICE | ice, compression, and elevation |
| ICF | intermediate care facility |
| ICF | intracellular fluid |
| ICG | Initiative for Chemical Genetics |
| ICG | idiopathic collapsing glomerulopathy |
| ICG | impedance cardiogram |
| ICG | impedance cardiography |
| ICH | immunocompromised host |
| ICH | intracerebral hemorrhage |
| ICH | intracranial hemorrhage |
| ICI | intracranial injury |
| ICL | intracorneal lens |
| ICM | intercostal margin |
| ICM | intercostal muscle |
| ICM | ischemic cardiomyopathy |
| ICN | infection control nurse |
| ICN | intensive care nursery |
| ICP | inductively coupled plasma |
| ICP | intercostal position |
| ICP | intracranial pressure |
| ICR | Individual Case Review |
| ICR | Institute for Cancer Research |
| ICR | iliac crests |
| ICR | intercaudate nucleus ratio |
| ICS | ileocecal sphincter |
| ICT | icterus |
| ICT | intensive conventional therapy |
| ICT | intracranial tumor |
| ICU | intensive care unit |
| ICU | intermediate care unit |
| ICV | internal cerebral vein |
| ICV | ileocecal valve |
| ICV | ileocolic vein |
| ICV | intracerebroventricular |
| ICW | in connection with |
| ICW | intact canal wall |
| ICW | intercellular water |
| ID | identification |
| ID | identify |
| ID | idiotype |
| ID | immunodiffusion |
| ID | induction delivery |
| ID | initial diagnosis |
| ID | initial dose |
| ID | intradermal |
| ID | iron deficiency |
| IDA | iron deficiency anemia |
| IDA | idamycin |
| IDAM | infant of drug abusing mother |
| IDB | inferior dental block |
| IDB | incomplete database |
| IDC | idiopathic dilated cardiomyopathy |
| IDD | insulin-dependent diabetes |
| IDD | intervertebral disk disease |
| IDDM | insulin-dependent diabetes mellitus |
| IDE | Investigational Device Exemption |
| IDE | insulin-degrading enzyme |
| IDE | inner dental epithelial |
| IDH | Infectious Diseases Hospital |
| IDH | intervertebral disc herniation |
| IDH | intradialytic hypotension |
| IDH | isocitrate dehydrogenase |
| IDI | Interpersonal Dependency Inventory |
| IDI | intrathecal drug infusion |
| IDK | internal derangement of knee |
| IDL | intermediate-density lipoprotein |
| IDM | infant of a diabetic mother |
| IDNA | iron-deficient, not anemic |
| IDO | idiopathic detrusor overactivity |
| IDP | initiate discharge planning |
| IDR | Idarubicin |
| IDR | immunodeficiency Resource |
| IDR | indermal reaction |
| IDR | idiosyncratic drug reaction |
| IDS | infectious disease service |
| IDT | intensive diabetes treatment |
| IDU | idoxuridine |
| IDU | injection drug user |
| IDU | intravenous drug user |
| IDU | illicit drug use |
| IDV | Indinavir |
| IDV | initial distribution volume |
| IE | immunoelectrophoresis |
| IE | induced emesis |
| IE | infectious enteritis |
| IE | inner ear |
| IEC | independent ethics committee |
| IEC | inpatient exercise center |
| IED | immune-enchancing diet |
| IEED | involuntary emotional expression disorder |
| IEF | International Eye Foundation |
| IEF | incontinence episode frequency |
| IEF | isoelectric focusing |
| IEH | involuntary emergency hospitalization |
| IEI | idiopathic environmental intolerance |
| IEL | internal elastic lamina |
| IEM | immune electron microscopy |
| IEN | intraepithelial neoplasia |
| IEP | idiopathic eosinophilic pneumonia |
| IES | Impact of Events Scale |
| IES | infected erythrocytes |
| IES | inferior esophageal sphincter |
| IES | inspiratory effort sensation |
| IF | I factor |
| IF | impact factor |
| IF | internal fixation |
| IF | interstitial fluid |
| IF | idiopathic flushing |
| IF | intrinsic factor |
| IFA | immunofluorescent assay |
| IFA | iron and folic acid |
| IFAT | immunofluorescence antibody test |
| IFC | inferior frontal cortex |
| IFC | interferential current |
| IFC | intracellular free calcium |
| IFE | immunofixation electrophoresis |
| IFG | impaired fasting glucose |
| IFI | invasive fungal infection |
| IFL | indolent follicular lymphoma |
| IFN | interferon |
| IFO | ifosfamide |
| IFO | in front of |
| IFOP | infrared fiber-optic probe |
| IFOS | ifosfamide |
| IFP | inflammatory fibroid polyps |
| IFRT | involved-field radiotherapy |
| IFSAC | Inventory of Functional Status After Childbirth |
| IFSE | internal fetal scalp electrode |
| IFSP | individualized family service plan |
| IgA | immunoglobulin A |
| IgA | infantile genetic agranulocytosis |
| IGCS | inpatient geriatric consultation services |
| IgD | immunoglobulin D |
| IGDE | idiopathic gait disorders of the elderly |
| IGDM | infant of gestational diabetic mother |
| IGE | idiopathic generalized epilepsy |
| IGE | impaired gas exchange |
| IGE | infantile gastroenteritis |
| IgE | immunoglobulin E |
| IGFA | indocyanine-green fundus angiography |
| IgG | immunoglobulin G |
| IGHL | inferior glenohumeral ligament |
| IGI | image guided implantology |
| IgM | immunoglobulin M |
| IGP | interstitial glycoprotein |
| IGR | intrauterine growth retardation |
| IGT | impaired glucose tolerance |
| IH | inguinal hernia |
| IH | infectious hepatitis |
| IH | indirect hemagglutination |
| IH | idiopathic hypercalciuria |
| IH | idiopathic hypersomnia |
| IH | immediate hypersensitivity |
| IH | in hospital |
| IHA | immune hemolytic anemia |
| IHA | intrahepatic arterial |
| IHC | idiopathic hypercalciuria |
| IHC | immobilization hypercalcemia |
| IHC | immunohistochemistry |
| IHD | ischemic heart disease |
| IHD | intrahepatic duct |
| IHD | intermittent hemodialysis |
| IHES | idiopathic hypereosinophilic syndrome |
| IHGK | immortalized human gingival keratinocytes |
| IHH | idiopathic hypogonadotrophic hypogonadism |
| IHH | intermittent hypercapnic hypoxia |
| IHI | Institute for Healthcare Improvement |
| IHO | idiopathic hypertrophic osteoarthropathy |
| IHP | idiopathic hypoparathyroidism |
| IHP | inverted hand position |
| IHP | isolated hepatic perfusion |
| IHP | idiopathic hypertrophic pachymeningitis |
| IHR | inguinal hernia repair |
| IHR | intrinsic heart rate |
| IHS | integrated healthcare system |
| IHS | Idiopathic Headache Score |
| IHT | insulin hypoglycemia test |
| IHU | inpatient hospice unit |
| IHW | inner-heel wedge |
| II | Image Intensification |
| II | insulin index |
| II | internal iliac |
| IICU | infant intensive care unit |
| IID | Insulin dependent diabetes |
| IID | infectious intestinal disease |
| IITN | idiopathic trigeminal neuralgia |
| IITN | Immune Tolerance Network |
| IITN | insecticide-treated bed net |
| IJ | ileojejunal |
| IJ | internal jugular |
| IJC | internal jugular catheter |
| IJD | inflammatory joint disease |
| IJO | idiopathic juvenile osteoporosis |
| IJP | internal jugular pressure |
| IJR | idiojunctional rhythm |
| IJT | idiojunctional tachycardia |
| IJV | internal jugular vein |
| IK | immobilized knee |
| IK | interstitial keratitis |
| IL | immature lungs |
| ILA | internal iliac artery |
| ILA | insulin-like activity |
| ILA | indirect latex agglutination |
| ILA | inferior lateral angle |
| ILB | incidental Lewy body |
| ILC | interstitial laser coagulation |
| ILC | invasive lobular cancer |
| ILCP | increased intracranial pressure |
| ILD | immature lung disease |
| ILD | interstitial lung disease |
| ILE | intravenous lipid emulsion |
| ILE | infantile lobar emphysema |
| ILF | indicated low forceps |
| ILI | influenza-like illness |
| ILM | internal limiting membrane |
| ILM | intubating laryngeal mask |
| ILP | independent living program |
| ILP | isolated limb perfusion |
| ILR | implantable loop recorder |
| ILS | intermittent light stimulation |
| ILS | idiopathic leucine sensitivity |
| ILS | idiopathic lymphadenopathy syndrome |
| ILS | increased life span |
| ILT | interstitial laser therapy |
| IP | interphalangeal |
| IP | intraperitoneal |
| IP | imaging plate |
| IP | induction period |
| IP | inpatient |
| IP | ice pack |
| IP | invasive procedure |
| IP | individualized plan |
| IP | incubation period |
| IPA | Invasive pulmonary aspergillosis |
| IPA | independent practice association |
| IPA | idiopathic pulmonary arteriosclerosis |
| IPB | initial pulmonary burden |
| IPB | injury-prone behavior |
| IPB | interpleural block |
| IPB | infrapopliteal bypass |
| IPC | Intermittent pneumatic compression |
| IPC | IFN-alpha producing cells |
| IPC | impression cytology |
| IPC | inferior parietal cortex |
| IPC | indirect pulp cavity |
| IPD | idiopathic Parkinson disease |
| IPD | inflammatory pelvic disease |
| IPD | intermittent peritoneal dialysis |
| IPF | idiopathic pulmonary fibrosis |
| IPF | inpatient psychiatric facility |
| IPG | immobilized pH gradient |
| IPH | idiopathic pulmonary hemosiderosis |
| IPH | interphalangeal |
| IPI | International Prognostic Index |
| IPJ | interphalangeal joint |
| IPK | intractable plantar keratosis |
| IPL | intense pulsed light |
| IPL | inferior parietal lobe |
| IPM | intranodal-palisaded myofibroblastoma |
| IPN | infantile periarteritis nodosa |
| IPN | interstitial pneumonia |
| IPOF | immediate postoperative fitting |
| IPOP | immediate postoperative prosthesis |
| IPP | inflatable penile prosthesis |
| IPP | intrapleual pressure |
| IPPA | inspection, palpation, percussion, andauscultation |
| IPPB | intermittent positive-pressure breathing |
| IPPE | initial preventive physical examination |
| IPPF | immediate postoperative prosthetic fitting |
| IPPI | interruption of pregnancy for psychiatricindication |
| IPPI | Immediate postplacental insertion |
| IPPI | Intensified Pulse Polio Immunization |
| IPPV | intermittent positive pressure ventilation |
| IPS | idiopathic pneumonia syndrome |
| IPT | Isoniazid preventive therapy |
| IPT | immediate patch test |
| IPT | immunoperoxidase technique |
| IPT | intended primary treatment |
| IPV | Infectious pustular vulvovaginitis |
| IPV | inactivated poliovirus vaccine |
| IPW | interphalangeal width |
| IQ | intelligence quotient |
| IQR | interquartile range |
| IR | immediate-release |
| IR | immunoreactive |
| IR | inferior rectus |
| IR | infrared |
| IR | insulin resistance |
| IR | internal reduction |
| IRA | infarct-related artery |
| IRB | Institutional Review Board |
| IRC | Indirect radionuclide cystography |
| IRC | inactive renin concentration |
| IRD | immune renal disease |
| IRE | internal rotation in extension |
| IRF | impaired renal function |
| IRF | inpatient rehabilitation facilities |
| IRF | internal rotation in flexion |
| IRH | idiopathic reactive hypoglycemia |
| IRH | Institute for Reproductive Health |
| IRH | intraretinal hemorrhage |
| IRI | immunoreactive insulin |
| IRM | insect resistance management |
| IRM | idiopathic recurrent miscarriage |
| IRM | immediate-release morphine |
| IRM | immunoreactive material |
| IRN | iterated rippled noise |
| IRNS | intercostal repetitive nerve stimulation |
| IROS | intracellular reactive oxygen species |
| IROS | ipsilateral routing of signals |
| IRP | intellectual property rights |
| IRR | infrared radiation |
| IRR | incidence rate ratio |
| IRR | intrarenal reflux |
| irreg | irregular |
| IRS | insulin receptor substrate |
| IRS | insulin-resistance syndrome |
| IRT | immunoreactive trypsin |
| IRV | inspiratory reserve volume |
| IRV | inverse ratio ventilation |
| IS | intercostal space |
| IS | international standards |
| IS | ileal segment |
| IS | immune serum |
| IS | in situ |
| IS | incentive spirometer |
| IS | induced sputum |
| ISA | intrinsic sympathomimetic activity |
| ISA | immunosuppressive activity |
| ISA | impaired self-awareness |
| ISA | ileosigmoid anastomosis |
| ISADH | inappropriate secretion of antidiuretic hormone |
| ISAM | infant of substance abusing mother |
| ISB | incentive spirometry breathing |
| ISC | carcinoma in situ |
| ISC | infant servo-control |
| ISC | infant skin control |
| ISC | intermittent self-catheterization |
| ISD | inhibited sexual desire |
| ISD | initial sleep disturbance |
| ISE | internal scalp electrodeinhibited sexual excitement |
| ISF | interstitial fluid |
| ISG | immune serum globulin |
| ISH | isolated systolic hypertension |
| ISI | Insulin Sensitivity Index |
| ISK | ileosigmoid knot |
| ISK | irritated seborrheic keratosis |
| ISMA | infantile spinal muscular atrophy |
| ISNA | iron-sufficient, not anemic |
| ISO | Inside-out |
| ISO | International Organization for Standardization |
| ISP | isoproterenol |
| ISP | ice structuring protein |
| ISP | idiopathic spontaneous pneumothorax |
| ISP | inferior spermatic plexus |
| ISQ | implant stability quotient |
| ISR | injection site reaction |
| ISS | idiopathic short stature |
| ISS | Injury Severity Score |
| ISS | irritable stomach syndrome |
| IST | immunosuppressive therapy |
| IST | inappropriate sinus tachycardia |
| IST | insulin shock therapy |
| ISU | intermediate surgical unit |
| ISW | interstitial water |
| IT | Intrathecal |
| IT | individual therapy |
| IT | inhalation therapy |
| IT | intensive therapy |
| IT | interdisciplinary Team |
| IT | intradermal test |
| IT | idiopathic thrombocythemia |
| IT | iliotibial |
| IT | immature teratoma |
| IT | immobility time |
| IT | immune Tolerance |
| ITA | individual treatment assessment |
| ITB | iliotibial band |
| ITC | Incontinence Treatment Center |
| ITC | isothermal titration calorimetry |
| ITC | inferior temporal cortex |
| ITD | impedance threshold device |
| ITE | insufficient therapeutic effect |
| ITE | in-the-ear |
| ITF | inpatient treatment facility |
| ITOC | intratracheal oxygen catheter |
| ITP | idiopathic thrombocytopenic purpura |
| ITQ | inferior temporal quadrant |
| ITR | intertrigeminal region |
| ITR | intraocular tension recorder |
| ITR | inverted terminal repetition |
| ITR | isolated testicular relapse |
| ITR | isotretinoin |
| ITS | intelligent testing strategies |
| ITT | identical twins together |
| ITT | insulin tolerance test |
| ITT | intention-to-treat |
| ITU | infant-toddler unit |
| ITU | intensive therapy unit |
| ITU | intensive treatment unit |
| ITVAD | indwelling transcutaneous vascular access device |
| ITZ | itraconazole |
| IUBT | intrauterine blood transfusion |
| IUC | idiopathic ulcerative colitis |
| IUC | intrauterine catheter |
| IUD | intrauterine death |
| IUD | intrauterine device |
| IUFB | intrauterine foreign body |
| IUGR | intrauterine growth retardation |
| IUI | intrauterine insemination |
| IULN | institutional upper limit of normal |
| IUP | intrauterine pregnancy |
| IUR | intrauterine retardation |
| IUS | Intermediate Units |
| IUS | intraoperative ultrasonography |
| IUS | intrauterine drug delivery system |
| IUS | intrauterine system |
| IUT | intersection-union test |
| IUT | intrauterine transfusion |
| IUTD | immunizations up to date |
| IV | intravenous |
| IV | in vitro |
| IV | influenza virus |
| IV | Interstitial volume |
| IV | interventricular |
| IV | intervertebral |
| IV | intravaginal |
| IV | intravascular |
| IV | intravenous bolus |
| IV | intravenous catheter |
| IV | intravertebral |
| IVA | initial visual acuity |
| IVA | interpretative value analysis |
| IVA | intervertebral angle |
| IVBAT | intravascular bronchoalveolar tumor |
| IVC | inferior vena cava |
| IVC | intravenous chemotherapy |
| IVC | intravenous catheter |
| IVD | instrumental vaginal delivery |
| IVD | intevertebral disk |
| IVD | intravenous dripor drug |
| IVET | in vivo expression technology |
| IVF | intervertebral foramina |
| IVF | intravenous fluid |
| IVF | in vitro fertilization |
| IVGG | intravenous gamma globulin |
| IVH | intravenous hyperalimentation |
| IVH | intraventricular hemorrhage |
| IVIG | intravenous immunoglobulin |
| IVJC | intervertebral joint complex |
| IVL | intravascular large B-cell lymphoma |
| IVL | intravascular lymphoma |
| IVL | intravascular lymphomatosis |
| IVL | intravenous lock |
| IVMP | intravenous methylprednisolone |
| IVNC | isolated ventricular noncompaction |
| IVO | intraoral vertical osteotomy |
| IVP | intravenous push |
| IVPB | intravenous piggyback |
| IVR | idioventricular rhythm |
| IVR | iliac vascular resistance |
| IVR | interventional radiology |
| IVR | interventional vascular radiology |
| IVR | intrarenal vascular resistance |
| IVR | intravaginal ring |
| IVRA | intravenous regional anesthesia |
| IVRO | intraoral vertical ramus osteotomy |
| IVS | inappropriate vasopressin secretion |
| IVS | intact ventricular septum |
| IVS | intraventricular septum |
| IVS | irritable voiding syndrome |
| IVT | idiopathic ventricular tachycardia |
| IVT | idioventricular tachycardia |
| IVT | intravenous transfusion |
| IVU | intravenous urogram |
| IVU | intravenous drug user |
| IW | inspiratory wheeze |
| IWL | insensible water loss |
| IWL | involuntary weight loss |