Human health and medicine

Expiratory Reserve Volume

Expiratory reserve volume (ERV) is the maximal air exhaled from functional residual capacity to residual volume; one of four lung volumes, spirometry-measured, and reduced earliest and most markedly in obesity, supine posture, and pregnancy.

Explantation

Explantation is the surgical removal of an implanted device, prosthesis, or transplanted tissue from the body, most often to treat infected cardiac device leads or remove breast implants.

Exploding head syndrome

Exploding head syndrome (EHS), also called episodic cranial sensory shock, is a benign parasomnia of sudden painless loud noises at sleep-wake transitions, first described in 1876, with variable prevalence and reassurance-based management.

Exploratory laparotomy

Exploratory laparotomy is an open surgical exploration of the abdomen through a midline incision, both diagnostic and therapeutic, most often performed as an emergency for bleeding, perforation, or trauma.

Exploratory surgery

Exploratory surgery is a diagnostic operation in which a surgeon opens a body cavity, usually the abdomen, to inspect organs directly when imaging has not produced a diagnosis.

EXPLORER-HCM trial

EXPLORER-HCM: phase 3 randomized double-blind placebo-controlled trial of mavacamten (Camzyos) in 251 adults with symptomatic obstructive hypertrophic cardiomyopathy; 37% vs 17% met the pVO2/NYHA composite endpoint at 30 weeks.

Exposure and response prevention

Exposure and response prevention (ERP) is a cognitive-behavioral therapy in which patients deliberately confront feared stimuli while refraining from compulsions, the first-line psychological treatment for obsessive-compulsive disorder, typically over 12 to 20 sessions.

Exposure keratitis

Exposure keratitis (exposure keratopathy, EK): corneal damage from dryness due to incomplete eyelid closure or poor blinking. Common in ICU patients (pooled prevalence 34%); treated with lubricants, moisture chambers, taping, tarsorrhaphy.

Exposure therapy

Exposure therapy, also called in vivo, imaginal, or interoceptive exposure and including flooding and ERP, is a behavior therapy for anxiety disorders, OCD, and PTSD that uses repeated confrontation with feared stimuli; mechanisms debated between habituation and inhibitory learning models.

EXPRED trial

EXPRED (Exercise and Prediabetes After Renal Transplantation, NCT04489043), a Spanish Hospital Universitario de Canarias program: exercise training reversed prediabetes in 60% of kidney transplant recipients in EXPRED-I, with randomized EXPRED-II ongoing.

Expressive aphasia

Expressive aphasia, also called Broca's aphasia or motor aphasia, is a nonfluent aphasia from left frontal lobe damage, with effortful telegraphic speech, relatively spared comprehension, and treatment by speech-language therapy.

Exsanguination

Exsanguination, also called exsanguinating hemorrhage or total blood loss, is rapid extreme blood loss leading to hemorrhagic shock; it causes nearly half of early trauma deaths and is treated with damage-control resuscitation.

Exstrophy-epispadias complex

Exstrophy-epispadias complex (EEC, BEEC), also called bladder exstrophy-epispadias complex: rare congenital malformation spectrum from epispadias to classic bladder exstrophy and cloacal exstrophy (OEIS), incidence about 1/30,000, treated by staged or primary surgical repair.

Exsufflation

Exsufflation is an airway-clearance technique in which a device applies negative pressure to the airway to simulate a cough and mobilize mucus, used mainly in neuromuscular disease.

Extended Radical Mastectomy

Extended radical mastectomy is a breast cancer operation adding chest wall and internal mammary node removal to the radical mastectomy, introduced by Jerome Urban in 1951.

Extended thymectomy

Extended thymectomy is an operation that removes the thymus gland together with the surrounding anterior mediastinal fat, from diaphragm to thyroid, used mainly to treat myasthenia gravis.

Extended-Wear Contact Lenses

Extended-wear contact lenses (continuous-wear lenses) are soft, usually silicone hydrogel, lenses approved for overnight wear from one to six nights up to 30 days; they carry a manyfold higher keratitis risk than daily wear.

Extensively drug-resistant mycobacterium tuberculosis

Extensively drug-resistant tuberculosis (XDR-TB) is MDR/RR tuberculosis resistant to any fluoroquinolone and bedaquiline or linezolid, per WHO's 2021 definition; 25,140 pre-XDR/XDR cases were notified in 2024, with treatment success around 40-54%.

ExtenZe

ExtenZe is an over-the-counter male enhancement dietary supplement sold as a proprietary herbal blend. Known for a $1.75M false-advertising settlement and FDA findings of undeclared sildenafil in Extenze Plus.

External carotid artery

External carotid artery (ECA): artery from the common carotid bifurcation (about C3-C4) supplying head and neck structures outside the skull; eight variable branches, common trunks, embolization and collateral pathways.

External cephalic version

External cephalic version (ECV) is a manual obstetric procedure in which a clinician presses on the pregnant woman's abdomen to turn a breech fetus head-down, performed from 36 to 37 weeks.

External dacryocystorhinostomy

External dacryocystorhinostomy (external DCR, EX-DCR) is an ophthalmic surgical procedure that treats nasolacrimal duct obstruction by creating a new tear-drainage pathway from the lacrimal sac into the nasal cavity.

External fixation

External fixation is a surgical technique that stabilizes broken bones with pins or wires through the skin, connected by an adjustable external frame, leaving soft tissues accessible.

External Fixators

An external fixator is an orthopedic device that stabilizes fractures with pins or wires through the bone, connected to a frame outside the skin that allows wound access.

External hirudiniasis

External hirudiniasis (leech infestation of the skin; ICD-11 1G02, ICD-10-CM B88.3) is painless skin attachment by bloodsucking leeches, causing prolonged bleeding from hirudin, itching, and possible allergic or Aeromonas infection; distinct from internal hirudiniasis (B83.4).

External quality assessment

External quality assessment, also known as proficiency testing, is a laboratory medicine procedure in which an external organization sends blinded specimens to laboratories and evaluates their results.

Externalizing disorder

An externalizing disorder is a mental disorder involving outward-directed behavior such as aggression, impulsivity, and rule breaking, spanning conditions like ADHD, conduct disorder, and antisocial personality disorder.

ExTINGUISH trial

ExTINGUISH (NCT04372615) is the first NIH-funded phase 2B randomized, double-blind, placebo-controlled trial of inebilizumab 300 mg, an anti-CD19 antibody, added to first-line therapy in 116 participants aged 12+ with moderate-to-severe anti-NMDAR encephalitis, primary endpoint mRS change at 16 weeks.

Extracapsular cataract extraction

Extracapsular cataract extraction is cataract surgery that removes the lens nucleus and cortex through a 10 mm limbal incision while leaving the capsule intact, usually followed by lens implantation.