Human health and medicine

BLISS-SC trial

BLISS-SC (BEL112341, NCT01484496) was a 52-week phase 3 trial of weekly subcutaneous belimumab 200 mg in 836 adults with active SLE, meeting its SRI-4 primary endpoint and enabling 2017 SC formulation approval.

Blister

Blister: a fluid-filled pocket in or under the epidermis caused by friction, burns, infection, or autoimmune disease; also called vesicle (small) or bulla (large); heals in one to two weeks.

Blister pack

Blister pack: pharmaceutical packaging of molded plastic or laminate cavities (PVC, PVDC, Alu-Alu) sealed with foil lidding, protecting tablets from moisture, oxygen, and light; FDA code BLPK, introduced with aluminum in the 1960s.

Bloating

Bloating: uncomfortable abdominal fullness or pressure, distinct from visible distension. Common causes include gut gas from FODMAPs, constipation, IBS, SIBO, and visceral hypersensitivity; low FODMAP diet is the best-supported therapy.

Block randomization

Block randomization is a clinical trial randomization method that assigns participants in small blocks, each containing equal allocations to every treatment group in random order, keeping group sizes balanced throughout enrollment.

Blomstrand lethal chondrodysplasia

Blomstrand lethal chondrodysplasia (BLC), also called Blomstrand osteochondrodysplasia, is a rare autosomal recessive skeletal dysplasia from PTH1R gene mutations, lethal before or shortly after birth.

Blonanserin

Blonanserin (Lonasen) is an atypical antipsychotic antagonist at dopamine D2/D3 and 5-HT2A receptors, approved for schizophrenia in Japan, South Korea, India, and China as tablets and a transdermal patch.

Blond

Blond (blonde) hair: low-eumelanin human hair color common in northern Europe (polygenic, KITLG enhancer and 200+ variants) and independently in Melanesia via a recessive TYRP1 93C allele at 26% frequency, absent outside Oceania.

Blood

Blood: specialized circulating body fluid of plasma, red blood cells, white blood cells, and platelets; about 55% plasma, carries oxygen, fights infection, clots; types A, B, AB, O with Rh factor.

Blood (journal)

Blood is a weekly peer-reviewed medical journal covering hematology, the study of blood and blood disorders. It has been the official journal of the American Society of Hematology since 1976.

Blood alcohol content

Blood alcohol content (BAC), or blood alcohol concentration, measures ethanol in blood in g/dL. Key facts: US per se limit 0.08 g/dL (Utah 0.05), crash risk 4x at 0.08, ADH zero-order elimination, blood/breath ratio 2100:1.

Blood bank

A blood bank collects, tests, separates, stores and distributes donated blood; covers component storage rules (red cells 1–6 °C up to 42 days, platelets 20–22 °C), NAT and pathogen reduction, the 2017 global supply gap, and 2023–2025 FDA policy changes.

Blood Banking

Blood banking: organized collection, testing, processing, storage, and distribution of blood for transfusion. Began with sodium citrate storage (1914–1915); now governed by WHO policy, mandatory HIV/hepatitis/syphilis screening, and hemovigilance.

Blood Cancer Journal

Blood Cancer Journal is an online-only, open-access peer-reviewed medical journal launched in 2011 that publishes research on hematologic malignancies, including leukemia, lymphoma, and myeloma, and is published by Springer Nature.

Blood cell

Blood cell: red blood cells, white blood cells, and platelets, the cellular elements of blood. Made in bone marrow from hematopoietic stem cells; red cells carry oxygen, white cells fight infection, platelets clot blood.

Blood Chemical Analysis

Blood Chemical Analysis: measurement of electrolytes, glucose, proteins, enzymes, and fats in blood, also called blood chemistry testing or metabolic panels (BMP, CMP), used to assess kidney, liver, and organ function and diagnose disease.

Blood Coagulation Tests

Blood coagulation tests, chiefly prothrombin time, activated partial thromboplastin time, and thrombin time, measure plasma clotting times to screen coagulation disorders, monitor heparin and warfarin via INR, and guide mixing studies.

Oct 20, 2026

Blood Component Transfusion

Blood component transfusion is the transfer of blood components such as red cells, platelets, and plasma from donor to recipient, one of the most common procedures worldwide.

Blood culture

Blood culture: laboratory incubation of patient blood in aerobic and anaerobic broth bottles to detect bacteremia and fungemia; 20–30 mL per adult set, automated CO2 detection since the 1970s BACTEC era, still the reference standard over rapid molecular assays.

Blood donation

Blood donation: voluntary collection of blood from healthy donors for transfusion. About 120.4 million donations yearly, over 85% voluntary unpaid; 450 mL per donation; risks include iron deficiency and vasovagal reactions.

Blood film

A blood film, or peripheral blood smear, is blood spread on a stained glass slide and examined under a microscope to assess blood cells and detect parasites.

Blood flow restriction training

Blood flow restriction training (BFRT, also called blood flow restriction exercise or KAATSU) applies an inflatable cuff to a limb during low-load exercise, producing muscle gains comparable to heavy lifting and making it valuable in rehabilitation.

Blood Flow Velocity

Blood flow velocity is the speed of blood in vessels (cm/s or m/s), measured mainly by Doppler ultrasound; flow = velocity × cross-sectional area. Key uses: stenosis grading, transcranial Doppler thresholds (vasospasm 180 cm/s, sickle cell 200 cm/s), angle-dependent errors.