Venous insufficiency is a condition where the flow of blood from
the leg back to the heart is impaired. The leg veins carry
oxygen deficient blood away from the legs and certain anatomical
features and physiological mechanisms in the leg enable the
unidirectional flow of blood to the heart. This includes the : -
Musculovenous pump (leg blood circulation pump) where the
contraction and relaxation of the leg muscles during activity
compress the veins thereby pushing the blood up the vessel. The
pulsating of the leg arteries also helps to keep blood flowing
in the veins. - Valves in the leg veins prevent backward flow as
the blood travels back to the heart. If blood attempts to flow
in the wrong direction within the vein (away from the heart) the
valve closes and prevents this. If the valves become
incompetent, then blood may flow backwards (retrograde flow) and
this is known as venous reflux. A blockage within a leg vein,
usually by a blood clot, can also hamper the outflow of blood
from the legs. Eventually bl