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Sickle cell disease with crisis
Sickle cell disease with crisis, ICD-11 code 3A51.2, covers sickle cell disease during a vaso-occlusive pain crisis: blocked blood flow causing severe pain, triggered by illness, dehydration, or altitude, treated with rapid analgesia.
Sickle cell disease without crisis
Sickle cell disease without crisis (ICD-10-CM D57.1; ICD-11 3A51.1) is the classification code for the chronic, stable state of sickle cell disease with no acute crisis; crisis codes D57.0x apply once a crisis occurs.
Sickle cell trait
Sickle cell trait (SCT, HbAS) is the carrier state of one sickle hemoglobin gene and one normal gene; usually symptomless, transmissible to children, rare risks under extreme exertion, dehydration, or low oxygen.
Sickle cell-beta-thalassemia disease
Sickle cell-beta-thalassemia disease (HbS/β-thalassemia), also called sickle beta-thalassemia, is an inherited sickle cell disease from one HbS gene plus one beta-thalassemia gene; the β0 form resembles HbSS sickle cell anemia, the β+ form is milder.
Sickness Impact Profile
The Sickness Impact Profile (SIP) is a self-administered questionnaire measuring how sickness changes everyday behavior, with 136 yes/no items in 12 categories, scored 0% to 100% dysfunction.
Siddha medicine (சித்த மருத்துவம்)
Siddha medicine (சித்த மருத்துவம்), also called Tamil medicine, is one of India's oldest traditional medical systems, practiced mainly in Tamil-speaking South India and regulated under the Ministry of Ayush.
Siddhayoga sangraha
Siddhayoga Sangraha (सिद्धयोगसंग्रह) is a compiled Ayurvedic formulary by Vaidya Yadavji Trikamji Acharya, first published 1978 by Baidyanath, gathering 256 formulations proven in fifty years of practice.
Side effect
Side effect: unintended effect of a medication beyond its therapeutic action; regulatory terms are adverse event (no causality needed) and adverse drug reaction (suspected causality), classified into types A through F and monitored via pharmacovigilance systems like FAERS, MedWatch, and WHO VigiBase.
Side Effects (2013 film)
Side Effects is a 2013 American psychological thriller directed by Steven Soderbergh, in which a depressed woman's antidepressant treatment leads to a killing, starring Rooney Mara, Jude Law, Channing Tatum, and Catherine Zeta-Jones.
Side stitch
Side stitch, or exercise-related transient abdominal pain (ETAP), is sharp, well-localized abdominal pain during exercise, most common in running and horse riding, worsened by pre-exercise eating, decreasing with age, and attributed mainly to parietal peritoneum irritation.
Sideroblastic anemia
Sideroblastic anemia is a group of inherited and acquired anemias defined by ring sideroblasts, iron-loaded erythroblasts in the marrow, with causes ranging from ALAS2 mutations to myelodysplastic syndrome.
Siderosis
Siderosis, or welder's lung, is a benign, nonfibrotic pneumoconiosis caused by inhaling iron oxide from welding fume or iron and hematite mine dust; x-ray shadows mimic silicosis but lung function is usually preserved.
SIDS
SIDS (sudden infant death syndrome) is the unexplained death of an infant under 1 year after complete investigation; a SUID subcategory. Back sleeping, launched via the 1994 Back to Sleep campaign, cut US SIDS rates over 50%.
sifap1 study
The sifap1 study (Stroke in Young Fabry Patients) was a European observational cohort study of 5,023 stroke patients aged 18 to 55 that found definite Fabry disease in 0.5%.
SighCO2 trial
SighCO2 (NCT05682937), a terminated before-after trial by Prince of Songkla University, tested sigh breaths during neonatal HFOV; in 30 intubated neonates, sighs lowered PaCO2 by 3.6 mmHg over 2 hours.
Sigmoid colectomy
Sigmoid colectomy is an operation that removes the sigmoid colon to treat diverticulitis, tumors, or volvulus, with laparoscopic resection now preferred in the elective setting.
Sigmoid colon
Sigmoid colon: S-shaped terminal segment of the large intestine, 25-40 cm, joining descending colon to rectum at S3; intraperitoneal via sigmoid mesocolon, supplied by IMA sigmoidal branches, prone to diverticulitis.
Sigmoidoscopes
Sigmoidoscopes, rigid or flexible endoscopes with a light and camera, examine the rectum and sigmoid colon. Flexible versions, introduced by Overholt in 1962, screen for distal colorectal cancer with low complication rates.
Sigmoidoscopy
Sigmoidoscopy (flexible sigmoidoscopy) is endoscopic examination of the rectum and lower colon with a flexible camera tube. Used for symptoms and CRC screening; RCTs show 28% mortality reduction, benefit limited to distal colon; perforation about 1 in 50,000.
Sigmund Freud
Sigmund Freud (1856–1939), Austrian neurologist and founder of psychoanalysis; born in Freiberg, Moravia, worked in Vienna, fled the Nazis in 1938, died in London; wrote The Interpretation of Dreams and Studies on Hysteria.
Signal-averaged ECG
Signal-averaged ECG (SAECG), also called high-resolution ECG, detects ventricular late potentials via beat averaging; used for post-infarction arrhythmia risk stratification, with high negative but low positive predictive value.
Signs and symptoms
Signs and symptoms: clinical manifestations of disease. A symptom is subjective, perceived by the patient; a sign is objective, observed by the clinician. Defined in MeSH D012816 and coded in ICD-10-CM R00-R99.
Signs and symptoms of HIV/AIDS
Signs and symptoms of HIV/AIDS: flu-like acute illness 2–4 weeks after infection, symptom-free clinical latency lasting about a decade, then AIDS with CD4 below 200 cells/mm3 and opportunistic infections; testing is the only reliable diagnosis.
Sigvotatug vedotin
Sigvotatug vedotin (PF-08046047, SGN-B6A) is Pfizer/Seagen's investigational integrin beta-6-directed antibody-drug conjugate with MMAE payload for NSCLC; its phase 3 SigVie-002 trial missed overall survival versus docetaxel, while frontline combination trials with pembrolizumab continue.
SIJ trial
SIJ trial (NCT06415461): a Phase 1 open-label dose-ranging University of Florida trial of CFL001 (PremierMaxCB-Platinum) cord blood product for symptomatic sacroiliac joint syndrome; nine adults dosed at 30, 60, and 90 x 10^6 TNC.
Sildenafil
Sildenafil (Viagra, Revatio) is a Pfizer-developed PDE5 inhibitor, first synthesized as UK-92,480 in 1989 for angina, approved March 27, 1998 as the first oral erectile dysfunction treatment, later repurposed for pulmonary arterial hypertension.
Silent brain infarction
A silent brain infarction, also called a silent stroke, is a brain infarct visible on MRI that never produced a recognized stroke; it becomes common with age.
Silent myocardial infarction
A silent myocardial infarction is a heart attack that causes no symptoms or only vague ones, recognized later on a routine ECG or imaging study.
Silent myocardial ischemia
Silent myocardial ischemia, also called silent ischemia, is reduced blood flow to the heart muscle without angina symptoms, the most common manifestation of coronary artery disease.
Silent sinus syndrome
Silent sinus syndrome, also called chronic maxillary atelectasis or imploding antrum syndrome, is a rare acquired disorder in which maxillary ostium occlusion creates negative sinus pressure, collapsing the orbital floor and causing painless enophthalmos and hypoglobus, treated mainly with endoscopic sinus surgery.