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Blood pressure
Blood pressure is the force of blood against artery walls, reported as systolic/diastolic in mm Hg; normal is under 120/80, high at 130/80 or above, measured by cuff methods and confirmed with ambulatory or home monitoring.
Blood pressure measurement
Blood pressure determination is noninvasive measurement of systolic and diastolic arterial pressure in mm Hg, by auscultatory Korotkoff sounds or validated oscillometric cuff devices, in office, home, and ambulatory settings.
Blood pressure monitoring
Blood pressure monitoring: repeated arterial BP measurement in office, home (HBPM), and 24-hour ambulatory (ABPM) settings to detect and manage hypertension, from Hales's 1733 equine experiment to validated oscillometric cuffs and not-yet-clinically-ready cuffless wearables.
Blood purification
Blood purification: extracorporeal therapies (hemodialysis, hemofiltration, apheresis, hemoperfusion, immunoadsorption) that remove toxins and pathogens from blood; also the Karger nephrology journal Blood Purification, ISSN 0253-5068, founded 1983.
Blood Safety
Blood safety: layered system protecting transfusion recipients via donor screening, testing for HIV, hepatitis B/C, syphilis, pathogen reduction, hemovigilance (SHOT, 1996), and WHO global blood system standards.
Blood smear
A blood smear is a test in which a thin layer of blood is spread on a slide, stained, and examined microscopically to evaluate blood cells and detect parasites.
Blood Specimen Collection
Blood specimen collection, usually called phlebotomy, is the drawing of a blood sample to assess its overall character or measure its cells, chemicals, or gases in the laboratory.
Blood substitute
Blood substitute, also called artificial blood or oxygen therapeutic agent, an infusible product carrying oxygen only. Two classes, HBOCs and perfluorocarbons; no FDA-approved product for human use, Hemopure approved in South Africa and Russia.
Blood sugar regulation
Blood sugar regulation: hormonal control of blood glucose by pancreatic insulin (lowering) and glucagon (raising), plus incretins, counterregulation, A1C and CGM monitoring, and diabetes treatment.
Blood test
A blood test, also called blood work or blood analysis, is a laboratory test measuring cells, chemicals, and proteins in blood, often part of a regular checkup.
Blood transfusion
Blood transfusion: intravenous infusion of donor blood or components (red cells, platelets, plasma) to treat anemia or blood loss. Safe since Landsteiner's 1901 ABO discovery; modern practice favors restrictive 7 g/dL thresholds.
Blood transfusion = Trasfusione del sangue
Blood transfusion = Trasfusione del sangue (Trasfusione del sangue) is SIMTI's bimonthly peer-reviewed transfusion medicine journal, ISSN 1723-2007/2385-2070, published in Milan, indexed in MEDLINE, Impact Factor 2.7 (2025), official journal of SIMTI and SETS.
Blood type
Blood type: classification of blood by ABO group (A, B, AB, O) and RhD status, discovered by Karl Landsteiner in 1901; determines transfusion compatibility, with O negative the universal red cell donor and 49 ISBT-recognized systems by 2026.
Blood typing and crossmatching
Blood typing and crossmatching are the laboratory procedures that establish a patient's ABO and Rh blood group, screen for antibodies, and confirm donor blood compatibility before transfusion.
Blood Urea Nitrogen
Blood urea nitrogen (BUN) is a blood test measuring urea nitrogen, a waste product of protein breakdown, used chiefly to check kidney function; normal values run about 6 to 20 mg/dL.
Blood vessel
Blood vessels are the arteries, veins, and capillaries that carry blood through the body in pulmonary and systemic circuits; about 60,000 miles total, with three-layered walls, venous valves, and roughly 70 percent of blood volume held in veins.
Blood Vessel Prosthesis
Blood vessel prosthesis (vascular graft): artificial conduit, mainly Dacron polyester or ePTFE, implanted to bypass or replace diseased arteries; pioneered by Voorhees in 1952, successful for large vessels, still limited below 6 mm by thrombosis and intimal hyperplasia.
Blood Vessel Prosthesis Implantation
Blood vessel prosthesis implantation is the surgical placement of a synthetic vascular graft, usually Dacron or ePTFE, to replace a diseased vessel or bypass a blockage.
Blood Viscosity
Blood viscosity, the internal resistance of whole blood to flow, is non-Newtonian and shear-thinning, governed by hematocrit, plasma fibrinogen, and red cell aggregation and deformability; it marks cardiovascular, hematological, and inflammatory risk.
Blood volume
Blood volume, also called volemia, is the total amount of blood circulating in the arteries, capillaries, veins, and heart, about 5 liters in an average adult, varying with body size.
Blood Volume Determination
Blood Volume Determination: indicator-dilution measurement of circulating blood volume using 51Cr-labeled red cells and radioiodinated albumin; also called blood volume analysis, expressed in L/kg.
Blood-borne disease
Blood-borne disease: infections transmitted through infected blood, chiefly HBV, HCV, and HIV. Covers transfusion screening, needlestick risk, OSHA standard, and global donation inequities.
Blood-oxygen-level-dependent imaging
Blood-oxygen-level-dependent (BOLD) imaging is a functional MRI technique that maps brain activity indirectly through blood oxygenation changes, first demonstrated by Seiji Ogawa at Bell Laboratories in 1990.
BLOOD-VALVES trial
The BLOOD-VALVES trial was a single-arm pilot study by Royal Brompton & Harefield NHS Foundation Trust in London testing bronchoscopic lung volume reduction for severe emphysema using valves plus autologous blood.
Blood–brain barrier
Blood–brain barrier (BBB): selective endothelial interface of brain capillaries with tight junctions and efflux pumps; blocks over 90% of small-molecule drugs; crossed via GLUT-1, receptor-mediated transcytosis (TfR1, LRP1), or focused ultrasound opening; term coined by Lewandowsky in 1900.
Bloodless Medical and Surgical Procedures
Bloodless medical and surgical procedures, also called transfusion-free medicine or patient blood management, provide care without allogeneic blood transfusion via anemia treatment, blood loss minimization, and oxygenation optimization, pioneered by Denton Cooley in 1962 for Jehovah's Witnesses.
Bloodletting
Bloodletting (venesection, phlebotomy): withdrawing blood as therapy, based on Galenic humoral theory, from ancient Egypt through the 1800s; abandoned after Louis's statistics and germ theory, surviving as therapeutic phlebotomy for hemochromatosis and polycythemia vera.
Bloom syndrome
Bloom syndrome (Bloom-Torre-Machacek syndrome, congenital telangiectatic erythema) is a rare autosomal recessive BLM gene disorder with severe growth deficiency, sun-sensitive facial rash, and early-onset cancer risk.
BLS-NEN-HCP trial
The BLS-NEN-HCP trial (NCT06001879) was a randomized controlled trial in Amman and Al-Zarqa, Jordan, comparing one-day simulation-based basic life support training with brochure-based training in 102 newly employed nurses.
Blue baby syndrome
Blue baby syndrome: infant cyanosis from cyanotic congenital heart disease, chiefly tetralogy of Fallot, or from infantile methemoglobinemia; first surgically treated by the 1944 Blalock-Taussig shunt at Johns Hopkins.