Human health and medicine

Fart lighting

Fart lighting, or pyroflatulence, is igniting flatus to produce a brief blue flame from gut-produced hydrogen and methane. Feasible only when gas concentrations exceed flammability limits; causes burn injuries and is a surgical hazard.

Fart walk

A fart walk, also called postprandial walking, is a casual walk taken shortly after eating, popularized by Canadian cookbook author Mairlyn Smith in a viral 2024 TikTok video.

Fascia

Fascia is a sheet or band of collagen-rich connective tissue beneath the skin that attaches, encloses, and separates muscles and organs, divided into superficial, deep, parietal, and visceral types.

Fascia iliaca compartment block

The fascia iliaca compartment block, or fascia iliaca block, is a regional anesthesia technique used mainly for pain control in hip fracture and hip and knee surgery.

Fascial plane block

A fascial plane block is a regional anesthesia technique injecting local anesthetic between fascial layers to numb multiple nerves, used in abdominal, chest, and breast surgery.

Fasciculation

Fasciculation, also called muscle twitching or benign fasciculation when isolated, is an involuntary visible contraction of one motor unit arising from the lower motor neuron; common in healthy people, a sign of ALS when paired with weakness, and part of the peripheral nerve hyperexcitability spectrum.

Fasciectomy

Fasciectomy is a surgical procedure that removes diseased fascia, performed most often to straighten fingers bent by Dupuytren's contracture; open partial fasciectomy is the mainstay treatment.

Fasciitis or fibromatosis

Fasciitis or fibromatosis (FB51.2) is an ICD-11 fibroblastic disorders code covering nodular fasciitis, also called pseudosarcomatous fibromatosis, a rare benign rapidly growing subcutaneous soft tissue tumor.

Fascioliasis

Fascioliasis, liver fluke disease caused by Fasciola hepatica and F. gigantica, a foodborne zoonotic neglected tropical disease spread by raw watercress and contaminated water, treated with triclabendazole.

Fasciotomy

Fasciotomy is an emergency surgical procedure that cuts the fascia enclosing a muscle compartment to lower pressure and restore blood flow, the only recognized treatment for acute compartment syndrome.

Fasedienol

Fasedienol (PH94B, Aloradine) is Vistagen's investigational intranasal pherine spray for acute treatment of social anxiety disorder; one positive Phase 3 (PALISADE-2) but three failed primary-endpoint trials.

Fasiglifam

Fasiglifam (TAK-875) is a Takeda GPR40/FFAR1 partial agonist for type 2 diabetes that lowered HbA1c with low hypoglycemia risk but was terminated in December 2013 during phase III trials due to drug-induced liver injury.

Fasinumab

Fasinumab (REGN475, SAR164877, MT-5547) is a fully human IgG4 anti-nerve growth factor monoclonal antibody developed by Regeneron with Teva and MTPC for osteoarthritis and chronic low back pain; effective in phase 3 trials but discontinued in 2022 over dose-dependent joint damage risk.

FAST (stroke)

FAST (Face, Arms, Speech, Time) is a mnemonic teaching laypeople to spot stroke signs and call an ambulance, developed in 1998 in Newcastle and extended as BE-FAST.

Fast Healthcare Interoperability Resources

Fast Healthcare Interoperability Resources (FHIR, "fire") is HL7's open API-based standard for exchanging health data via modular resources and RESTful interfaces. First presented 2012; R5 (2023) has 157 resource types; FHIR R4 is mandated for US ONC certification.

Fast spin echo

Fast spin echo (FSE), also called turbo spin echo (TSE), is an MRI pulse sequence, based on the 1986 RARE technique, that is the workhorse for T2-weighted clinical MRI.

FAST study

FAST study (French Prospective Anterior Cruciate Ligament Reconstruction Cohort Study, NCT02511158): a single-center prospective Paris cohort begun 2012 following knee ligament reconstruction patients for re-tear, function, and 20-year osteoarthritis outcomes.

FAST-MAG trial

FAST-MAG (Field Administration of Stroke Therapy–Magnesium) was a NINDS-funded phase 3 trial (2005–2013, 1,700 patients, Los Angeles and Orange counties) testing paramedic-initiated magnesium sulfate within 2 hours of stroke onset; safe and fast but no 90-day disability benefit.

Oct 20, 2026

FAST-MI 2010 study

FAST-MI 2010 was a nationwide French registry of 4169 heart attack patients in 213 centers, conducted by the French Society of Cardiology and followed for up to 10 years.

Fasting

Fasting is abstinence from food or drink for religious, ethical, or health purposes; intermittent fasting forms include ADF, 5:2, and time-restricted eating, which trials show is roughly equal to calorie restriction for weight loss.

Fat embolism syndrome

Fat embolism syndrome (FES): fat globules entering the circulation after long-bone fractures, orthopedic surgery, or cosmetic fat procedures, causing the triad of hypoxia, neurological dysfunction, and petechial rash 24–72 hours after injury; diagnosis by Gurd criteria, supportive care.

Fat hypertrophy

Fat hypertrophy (ICD-11 EF02.0, insulin-induced lipohypertrophy) is focal enlargement of subcutaneous fat from enlarged adipocytes, caused by repeated insulin injections, corticosteroids, or antiretrovirals, and impairing insulin absorption.

Fat necrosis of breast

Fat necrosis of the breast, also called breast fat necrosis, is a benign inflammatory process of breast fat caused by trauma, surgery, biopsy, or radiation that mimics breast cancer on exam and imaging; diagnosed mainly by mammography, it carries no increased cancer risk.

Fat pad sign

Fat pad sign (sail sign): radiographic displacement of the elbow's intracapsular anterior and posterior fat pads by joint effusion, indicating occult fracture after trauma; posterior pad visibility is always abnormal.

Fat-Restricted Diet

A fat-restricted diet is an eating pattern limiting fat to under 30% of daily calories, with saturated fat under 10%, used in obesity care and for pancreatitis.

Fatal insomnia

Fatal insomnia, fatal familial insomnia (FFI) and sporadic fatal insomnia, fatal thalamic prion disease destroying sleep, caused by PRNP D178N with Met129 in the familial form; death within about a year, no approved treatment.

Fatigue

Fatigue: lack of energy and reduced physical or mental capacity, distinct from sleepiness (tendency to fall asleep). Classified as secondary, physiologic, or chronic; measured mainly by rating scales; treated with exercise, sleep hygiene, and cause-directed care.

Fatigue fracture of vertebra

Fatigue fracture of vertebra (ICD-11 FA72.3) is a stress fracture of spinal bone from repetitive submaximal load on normal bone, chiefly affecting the pars interarticularis, pedicle, and sacrum in athletes; distinct from osteoporotic insufficiency fractures.

Fatty acid hydroxylase-associated neurodegeneration

Fatty acid hydroxylase-associated neurodegeneration (FAHN, SPG35) is a very rare autosomal recessive NBIA disorder caused by FA2H mutations, with childhood-onset dystonia, spastic paraplegia, ataxia, optic atrophy, and globus pallidus iron.