It can refer to:
- The interior of a vessel, such as the central space in an artery or vein through which blood flows.
- The interior of the gastrointestinal tract
- The pathways of the bronchi in the lungs
- The interior of renal tubules and urinary collecting ducts
- The pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the fallopian tubes
Transluminal procedures are procedures occurring through lumina, including: