Human health and medicine

Suppressed lactation

Suppressed lactation: deliberate prevention or cessation of milk production after childbirth in non-breastfeeding women, also called lactation inhibition. Managed physiologically (breast support, comfort expression) or with drugs such as bromocriptine and cabergoline; distinct from agalactia (JB46.3).

Suppressive antiretroviral therapy

Suppressive antiretroviral therapy (ART) is the combination of antiretroviral drugs that keeps a person's HIV viral load undetectable, halting disease progression and preventing sexual transmission of the virus.

Supracervical hysterectomy

Supracervical hysterectomy is an operation that removes the uterine corpus while leaving the cervix in place, used mainly for benign disorders such as fibroids and abnormal bleeding.

Suprachiasmatic nucleus

Suprachiasmatic nucleus (SCN), hypothalamic master circadian pacemaker above the optic chiasm, ~20,000 neurons, intrinsic period ~24.2 h, light-entrained via the retinohypothalamic tract, synchronizes peripheral clocks and melatonin rhythms.

Supraclavicular brachial plexus block

The supraclavicular brachial plexus block, or supraclavicular block, is a regional anesthesia technique injecting local anesthetic above the clavicle to numb the arm and shoulder.

Supraclavicular lymph nodes

Supraclavicular lymph nodes (nodi lymphoidei supraclaviculares): 4-12 nodes above the clavicle draining breast, lung, esophagus, and abdomen; the left Virchow node (Troisier sign) signals metastatic cancer in 54-85% of enlargements.

Supracondylar fracture of humerus

Supracondylar humerus fracture, pediatric distal humerus fracture above the elbow, most common childhood elbow injury, Gartland types I-IV, treated by casting or closed reduction with percutaneous pinning.

Supraglottoplasty

Supraglottoplasty is a surgical procedure in otolaryngology that removes or reduces abnormal supraglottic laryngeal tissue to relieve the airway obstruction caused by laryngomalacia, the most common cause of stridor in infants.

Supramalleolar osteotomy

Supramalleolar osteotomy is a joint-preserving orthopedic procedure that cuts and realigns the tibia just above the ankle to shift load onto preserved cartilage in asymmetric ankle arthritis.

Suprapubic cystostomy

Suprapubic cystostomy is a urological procedure that places a catheter through the lower abdominal wall into the bladder to drain urine, used when urethral catheterization is not possible.

Suprascapular nerve block

A suprascapular nerve block (SSNB) is a regional anesthesia procedure injecting local anesthetic near the suprascapular nerve, which carries about 70% of shoulder sensation, to relieve shoulder pain.

Supraspinatus muscle

Supraspinatus muscle: rotator cuff muscle of the shoulder, originating in the supraspinous fossa of the scapula and inserting on the greater tubercle of the humerus; initiates 0-15 degrees of arm abduction, innervated by the suprascapular nerve (C5, C6), and the cuff tendon most prone to tears.

Supratrochlear lymph nodes

Supratrochlear (epitrochlear, cubital) lymph nodes: 1–2 superficial nodes 4–5 cm above the medial epicondyle draining the medial fingers and forearm to the axilla; palpable nodes over 0.5 cm are abnormal.

Supravalvular aortic stenosis

Supravalvular aortic stenosis (SVAS), also called supravalvar aortic stenosis or elastin arteriopathy, is congenital narrowing of the ascending aorta above the aortic valve, caused by ELN gene mutation or deletion at 7q11.23, alone or in Williams-Beuren syndrome.

Supraventricular tachycardia

Supraventricular tachycardia (SVT): fast heart rhythms above 100 bpm arising at or above the His bundle, including AVNRT, AVRT, and focal atrial tachycardia; atrial fibrillation excluded. Treated with adenosine acutely and catheter ablation curatively.

Suprofen

Suprofen (R-25061, Suprol, Profenal) is a propionic acid NSAID related to ibuprofen that inhibits prostaglandin synthesis. Its oral capsules were withdrawn worldwide in May 1987 over a flank pain and renal failure syndrome; the 1% ophthalmic solution for surgical miosis also left the market.

Suptavumab

Suptavumab (REGN-2222), a Regeneron human monoclonal antibody against RSV F protein antigenic site V, failed its 2015-2017 phase 3 infant trial when naturally emerging RSV-B strains with L172Q and S173L epitope mutations abolished neutralization; development was discontinued in 2017.

Sural nerve

Sural nerve: purely sensory lower-leg cutaneous nerve formed mainly by union of the medial sural cutaneous and peroneal communicating nerves; standard site for nerve conduction studies, nerve biopsy, and graft harvesting.

Suramin

Suramin (Germanin, Bayer 205) is a polysulfonated naphthylurea drug developed by Bayer in the 1910s; it remains in use for early-stage sleeping sickness.

Suraxavir marboxil tablets

Suraxavir marboxil (玛舒拉沙韦片, Yisuda, GP681) is a Chinese class 1 anti-influenza drug approved March 2025; an oral PA endonuclease inhibitor prodrug for uncomplicated influenza A and B in people 12 and older.

Surface ablation (ophthalmology)

Surface ablation is a flapless refractive surgery technique in which the corneal epithelium is removed and an excimer laser reshapes the cornea, preferred for thin corneas and patients at risk of flap dislocation.

Surface chemistry of neural implants

Surface chemistry of neural implants: coatings (Pt, IrOx, PEDOT, graphene, hydrogels, drug-releasing layers) on neural electrodes that lower impedance, raise charge capacity, and suppress glial scar formation at the electrode–tissue interface.

Surfactant therapy

Surfactant therapy is the administration of exogenous pulmonary surfactant into the lungs, principally of premature newborns, to treat respiratory distress syndrome, reducing mortality most in infants under 30 weeks' gestation.

SURGCOM study

SURGCOM (NCT07621198), Postoperative Complications in Major Surgery, is a prospective multicenter observational cohort in low- and middle-income settings developing a risk prediction model for 30-day major postoperative complications and mortality.

Surgeon

Surgeon: a physician who performs operations after medical school plus 5+ years of surgical residency (US) or 10+ years of UK training. Covers specialties, case minimums, pay, robotics, attrition, and workforce shortages.

Surgeon General of the United States

The Surgeon General of the United States is the government's leading spokesperson on public health and head of the U.S. Public Health Service Commissioned Corps.

Surgery

Surgery: operative treatment of disease and injury, transformed by ether anesthesia (1846), Lister's antisepsis, curare (1942), the WHO safety checklist, and modern robotic, AI-assisted, and telesurgical techniques.

Surgery for idiopathic scoliosis

Surgery for idiopathic scoliosis is the operative correction of an unexplained lateral spinal curvature, by spinal fusion or, in growing children, growth-friendly implants; curves over 40° typically warrant surgery.

Surgical ablation

Surgical ablation is a treatment that destroys targeted tissue, such as liver tumors or arrhythmogenic heart tissue, in place using heat, cold, electric fields, or focused ultrasound.