For diffusion to occur , which condition must be met ?

The diffusion is a biochemical process in which the molecules move from high concentration to low concentration. The occurrence of diffusion happens when there is high kinetic energy between the molecules of a substance occurs then this is a condition at which the diffusion of molecules takes place. The diffusion takes place in many organs in the body like diffusion of water, salt and other waste products occur in kidney and diffusion of oxygen and carbon takes place in the lungs of the human body.

Dynamic equilibrium must exist.