Human health and medicine

Interscalene nerve block

The interscalene nerve block is a regional anesthesia technique that injects local anesthetic between the scalene muscles of the neck to numb the shoulder and upper arm for surgery.

Intersex medical interventions

Intersex medical interventions, also called intersex surgery, are surgical or hormonal procedures on people born with sex characteristics that differ from typical male or female bodies.

Intersphincteric resection

Intersphincteric resection (ISR) is an operation for very low rectal cancer that removes the rectum and part of the internal anal sphincter, avoiding a permanent colostomy.

Interstitial cystitis

Interstitial cystitis (IC), also called bladder pain syndrome, is a chronic condition causing bladder pain, urinary urgency, and frequent urination, affecting 4 to 12 million Americans.

Oct 20, 2026

Interstitial emphysema (pulmonary interstitial emphysema, PIE; ICD-11 CB40.3, ICD-10-CM J98.2) is air within lung connective tissue sheaths and septa from alveolar rupture, mainly in ventilated premature neonates and as ventilator-induced barotrauma in adults.

Interstitial granulomatous dermatitis with arthritis

Interstitial granulomatous dermatitis with arthritis (IGDA, Ackerman syndrome), rare granulomatous skin and joint disorder, ORPHA:79099, rope sign, linked to rheumatoid arthritis, lupus, drugs, and malignancy.

Interstitial lung disease

Interstitial lung disease (ILD): a group of disorders scarring the lung interstitium, impairing oxygen transfer; about 3 per 10,000 US diagnoses yearly. Includes IPF, classified by ATS/ERS statements, treated with antifibrotics nintedanib and pirfenidone.

Interstitial lung disease-nephrotic syndrome-epidermolysis bullosa syndrome

ILNEB syndrome (OMIM 614748, ORPHA:306504) is an autosomal recessive ITGA3 disorder of infancy combining interstitial lung disease, nephrotic syndrome, and epidermolysis bullosa; about 11 patients reported, several milder variants survive.

Interstitial lung diseases associated with connective tissue diseases

CTD-ILD, also called connective tissue disease-associated interstitial lung disease (ICD-11 CB05.1), is immune-mediated lung inflammation and fibrosis complicating rheumatoid arthritis, systemic sclerosis, lupus, myositis, Sjögren, and MCTD; diagnosed by HRCT and treated with immunosuppression and antifibrotics.

Interstitial nephritis

Interstitial nephritis (tubulointerstitial nephritis), inflammation of kidney interstitial tissue causing AKI; mostly drug-induced (60-70%), diagnosed by biopsy, treated with drug withdrawal and sometimes corticosteroids.

Interstitial photodynamic therapy

Interstitial photodynamic therapy is a cancer treatment in which optical fibers placed inside a tumor deliver light that activates a photosensitizing drug, destroying tissue from within.

InterTAK study

InterTAK study (International Takotsubo Registry), founded 2011 at University Hospital Zurich, is the largest multicenter registry of takotsubo syndrome, with over 3,500 patients from 56 sites in 18 countries; it produced the InterTAK Diagnostic and Prognostic Scores.

Intertrigo

Intertrigo is inflammatory dermatitis of skin folds caused by friction, heat, and moisture, often secondarily infected by Candida; common in obesity and diabetes, with weak treatment evidence.

Intertrochanteric fracture of femur

Intertrochanteric fracture of femur (ICD-11 NC72.30): extracapsular hip fracture between the greater and lesser trochanters, AO/OTA 31A, common in osteoporotic elderly; treated by sliding hip screw or intramedullary nail, with 20-30% one-year mortality.

Interval appendectomy

Interval appendectomy is the planned, elective removal of the appendix 8 to 12 weeks after complicated appendicitis, such as an appendiceal abscess, was treated successfully without immediate surgery.

Interval cytoreductive surgery

Interval cytoreductive surgery, also called interval debulking surgery, removes advanced ovarian cancer after about 3 cycles of neoadjuvant chemotherapy, achieving higher complete-resection rates with less perioperative harm than primary surgery.

Interval debulking surgery

Interval debulking surgery is cytoreductive surgery for advanced ovarian cancer performed after a few cycles of neoadjuvant chemotherapy, followed by further chemotherapy of the same type.

Interval training

Interval training: exercise alternating intense work bouts with recovery periods, including HIIT, SIT, and RST. Developed early 20th century (Fartlek, German interval method); improves VO2max comparably to continuous training in less time.

Intervention mapping

Intervention mapping is an iterative six-step protocol for planning, developing, and evaluating theory- and evidence-based health promotion and public health interventions, first published in 1998.

Interventional cardiology (specialty)

Interventional cardiology, a cardiology subspecialty also called percutaneous cardiovascular intervention, uses catheter-based techniques for coronary, valvular, structural, and peripheral disease; founded on Gruentzig's 1977 angioplasty and the 1986 stent era.

Interventional Magnetic Resonance Imaging

Interventional MRI (iMRI, MR-guided interventional procedures): minimally invasive procedures guided by magnetic resonance imaging, emerging in the late 1980s; used for breast/prostate biopsy, tumor ablation, and cardiac procedures; no ionizing radiation but RF-heating and access challenges.

Interventional neuroradiology

Interventional neuroradiology is a medical specialty that diagnoses and treats blood vessel diseases of the brain, spine, head, and neck by navigating catheters through arteries under imaging guidance.

Interventional radiology

Interventional radiography (interventional radiology, IR): image-guided minimally invasive procedures using fluoroscopy, CT, and ultrasound. Founded on Seldinger's 1953 technique and Dotter's 1964 angioplasty; evolved from diagnostic angiography to a therapeutic clinical specialty.

Interventional study design

An interventional study is a research design in which investigators deliberately assign an intervention, such as a drug or device, to participants; the randomized controlled trial is the reference-standard form.

Interventional trial

An interventional trial is a clinical study in which researchers assign participants to receive an intervention, such as a drug or procedure, and measure its effect on health outcomes.

Interventional Ultrasonography

Interventional ultrasonography (interventional ultrasound): diagnostic and therapeutic procedures such as biopsy, drainage, catheterization, and ablation performed under real-time ultrasound guidance; first introduced in Europe, 1972 first clinical use, low complication rates.

Interventricular septum

Interventricular septum (septum interventriculare): the muscular and membranous wall separating the heart's left and right ventricles; carries the bundle of His, supplied mainly by the LAD, and the site of ventricular septal defects.

Interventricular septum aneurysm

Interventricular septum aneurysm (membranous ventricular septal aneurysm, MVSA): rare congenital outpouching of the membranous interventricular septum, about 0.3% of congenital heart disease, often incidental, with risks of block, tachycardia, thromboembolism.

Intervertebral disc

Intervertebral disc (IVD): fibrocartilaginous joint between vertebral bodies; 23 discs in the adult spine, each with nucleus pulposus, annulus fibrosus, and cartilaginous endplates; nucleus derives from the notochord; disc is avascular and prone to early degeneration.