| BSI | behavior status inventory; blood stream infection; borderline syndrome index; bound serum iron; brai... |
|---|---|
| BSO | bilateral sagittal osteotomy; bilateral salpingo-oophorectomy; British School of Osteopathy; butathi... |
| BSU | Bartholin, Skene, urethral [glands]; basic structural unit; British standard unit |
| BThU | British thermal unit |
| BTU | British thermal unit |