FAI (femoroacetabular impingement)

FAM (fertility awareness method)

FAMA (Fellow of the American Medical Association)

FANA (fluorescent antinuclear antibodies)

FAP (familial adenomatous polyposis)

FAPA (Fellow of the American Psychological Association)

FAS (fetal alcohol syndrome)

fasc (fasciculus)

FAX (facsimile)

FB (finger breadths)