Normal Vein Anatomy
Healthy veins work in conjunction with your leg muscles against the effects of gravity. They work together to pump returning blood to the heart (the skeletal-muscle pump).
Types of Veins
The veins in the leg are broken down into three types of veins. These are: your Surface Veins, Truncal Veins and the Deep Veins.
The Surface Veins start at the fine capillary level within the first 1 to 5 mm of the skin layer. This component of the venous system is mainly responsible for the visible blood vessels on the surface of skin. These small vessels ultimately reach and drain into the Truncal Veins.
The Truncal Veins convey most, if not all, the surface blood into the deep system and this accounts for approximately 15 percent of all the blood returned to the heart from the legs.
The Deep Venous system, as the name suggests, lies deep in between the muscle layers. This component of the venous system is responsible for returning large volumes of blood to the heart.
Disruption to this system results in severe symptoms such as; leg swelling, large varicose veins, skin scarring, skin pigmentation and skin ulceration. It is unfortunate that treatment options for the deep system are very limited.
What Can Go Wrong
Unlike arteries, veins contain valves that make sure that the blood flows at a very low pressure. But when these valves become damaged and fail to open or close completely, blood flow is altered and pressure in the veins increases. This leads to gradual enlargement of the veins causing Varicose Veins.
When veins become swollen or Varicose, the leaflets of the valves no longer meet properly. When the valves do not work (Vascular Incompetence) or when a damaged valve allows blood to flow backwards (Vascular Reflux) causing the vein to enlarge are generally referred to as Vascular Disease.