Human health and medicine

Intermittent explosive disorder

Intermittent explosive disorder (IED), a DSM-5 disruptive, impulse-control disorder, features recurrent impulsive aggressive outbursts disproportionate to provocation; US lifetime prevalence 5.4–7.3%, onset in adolescence, treated with CBT and fluoxetine.

Intermittent fasting

Intermittent fasting, also called intermittent energy or calorie restriction, alternates fasting and eating periods, with time-restricted eating, alternate-day fasting, and the 5:2 diet as its main forms.

Intermittent hydrarthrosis

Intermittent hydrarthrosis, or periodic synoviosis, is a rare rheumatologic disease of recurrent, self-remitting knee effusions with fixed periodicity, absent systemic symptoms, no joint damage, and a subset linked to MEFV autoinflammatory mutations.

Intermittent mandatory ventilation

Intermittent mandatory ventilation (IMV) is a ventilator mode delivering mandatory breaths at a set rate while the patient breathes spontaneously between them, used for weaning.

Intermittent pneumatic compression

Intermittent pneumatic compression (IPC) is a treatment in which inflatable leg cuffs rhythmically inflate and deflate to squeeze blood from deep veins, used mainly to prevent venous thromboembolism in hospitalized and surgical patients.

Intermittent Pneumatic Compression Devices

Intermittent pneumatic compression (IPC) devices, also called vasopneumatic or sequential compression devices, pump air into limb cuffs to boost venous flow and fibrinolysis, preventing DVT and treating edema, lymphedema, and peripheral artery disease.

Oct 20, 2026

Intermittent Positive-Pressure Breathing

Intermittent positive-pressure breathing (IPPB) delivers positive pressure during inspiration in spontaneously breathing patients for lung expansion, secretion clearance, and aerosol therapy; distinct from IPPB nerve block and from IPPV on ventilators.

Intermittent renal replacement therapy

Intermittent renal replacement therapy (IRRT) is dialysis-based kidney support for acute kidney injury in critically ill patients, delivered in sessions of a few hours, typically three per week, until kidney function recovers.

Oct 20, 2026

Intermittent strabismus

Intermittent strabismus (ICD-11 9C80.3), chiefly intermittent exotropia, is an episodic eye misalignment controlled by fusion, appearing with fatigue, illness, or distance viewing; treated by observation, patching, over-minus lenses, or surgery.

Intermittent theta burst stimulation

Intermittent theta burst stimulation (iTBS) is a patterned form of repetitive transcranial magnetic stimulation, delivering bursts of three pulses in sessions lasting about 3 minutes.

Intermittent urethral catheterization

Intermittent urethral catheterization, also known as clean intermittent catheterization, drains the bladder with a catheter passed through the urethra several times a day, often by patients themselves.

Intermittently scanned continuous glucose monitoring

Intermittently scanned continuous glucose monitoring (isCGM), also called flash glucose monitoring, is a diabetes monitoring method in which a wearable sensor displays readings only when scanned.

Internal bleeding

Internal bleeding (hemorrhage) is blood loss inside the body from injured vessels or organs. Key facts: life-threatening within hours, shock signs, CT diagnosis, damage control resuscitation, embolization or surgery.

Internal capsule

The internal capsule (capsula interna) is a compact band of white matter in each cerebral hemisphere where a small stroke can paralyze the opposite side of the body.

Internal carotid artery

Internal carotid artery (ICA): terminal branch of the common carotid artery supplying the brain and eye; seven segments C1–C7, first cerebral artery to form embryologically (day 24), ends as anterior and middle cerebral arteries.

Internal derangement of knee

Internal derangement of the knee (IDK), ICD-11 FA33 / ICD-10 M23, is a chronic knee disorder from meniscal tears or cruciate ligament rupture causing pain, instability, or locking; term coined by William Hey in 1803.

Internal Family Systems Model

Internal Family Systems (IFS) is a psychotherapy model by Richard C. Schwartz, from the mid-1980s, treating the mind as parts (exiles, managers, firefighters) led by a core Self; evidence is promising but limited, mainly pilot trials for depression, PTSD, and chronic pain.

Internal fixation

Internal fracture fixation, combined with surgical realignment as open reduction and internal fixation (ORIF), holds broken bones together with implanted screws, plates, wires, or rods inside the body.

Oct 20, 2026

Internal Fixators

Internal fixators are implants, including plates, screws, nails, rods, wires, and pins, placed inside the body to hold fractures in alignment during healing; used in ORIF surgery, historically from Hansmann, Lane, and Lambotte, with steel and titanium as main materials.

Internal iliac artery

Internal iliac artery (hypogastric artery), terminal branch of the common iliac artery supplying the pelvis; divides into anterior and posterior trunks, mean length 39.95 mm, diameter 6.86 mm, with Adachi Type I branching in about 56% of people.

Internal jugular vein

Internal jugular vein (vena jugularis interna): paired carotid-sheath vein draining skull, brain, face, and neck to the brachiocephalic vein; JVP window and central access site with higher infection but fewer malpositions than subclavian.

Internal limiting membrane flap technique

The internal limiting membrane flap technique is a vitreoretinal surgical maneuver in which an ILM remnant is inverted over a macular hole to promote its closure.

Internal Mammary-Coronary Artery Anastomosis

Internal mammary-coronary artery anastomosis, also called internal thoracic artery grafting, is the original form of coronary artery bypass surgery, first performed clinically by Kolesov in 1964; the LIMA-to-LAD graft is now the standard CABG conduit.

Internal medicine

Internal medicine: the adult-medicine specialty practiced by internists, covering diagnosis and care across all organ systems; three-year US residency, ABIM certification since 1936, subspecialties, hospitalists, and European five-year training.

Internal ophthalmoplegia

Internal ophthalmoplegia (ICD-11 9D01.0) is paralysis of the iris sphincter and ciliary muscle causing mydriasis and lost accommodation from parasympathetic disruption; distinct from internuclear ophthalmoplegia, a brainstem gaze disorder.

Internal thoracic artery

The internal thoracic artery, also called the internal mammary artery, is a paired artery from the subclavian artery that supplies the anterior chest and upper abdominal walls.

Internal thoracic vein

Internal thoracic vein (vena thoracica interna, internal mammary vein): paired chest wall vein draining breast, pericardium, diaphragm, and anterior thorax into the brachiocephalic veins; often double, with xiphoid venous arch, used in flap reconstruction.

International Brain Research Organization

The International Brain Research Organization (IBRO), founded in 1961 with UNESCO support, is a global federation of neuroscience societies that funds training, exchanges, and collaborative research, especially in economically disadvantaged countries.

International Classification of Diseases

The International Classification of Diseases (ICD) is the World Health Organization's international standard for coding diseases and causes of death; its current revision, ICD-11, took effect in 2022.