Varicose veins are visibly dilated superficial veins of the lower limbs. It is not always only a cosmetic problem as formation of varices may be caused by other diseases and in addition, venous varices can have further complications.
To fully understand the causes of varicose veins, it is necessary to mention basic anatomy of the venous system of the lower limbs. The venous blood is drained by two venous systems – the superficial and deep veins. The deep system is able to transport larger amount of blood and it is connected to the surface system with connecting veins. The veins of the lower limbs are equipped with one-way flaps that allow the blood to flow in only one direction (out o the limbs). The connecting veins have also valves that allow one-way blood flow from the superficial venous system to the deep veins and not in the opposite direction. In addition to the valves, the proper blood flow is ensured by the local muscle pump. Contractions of local muscles compress the veins and push the blood in the right direction.
The causes of varicose veins can be numerous and they usually combine. Superficial veins dilate and get a sac-like shape when overloaded by a large volume of blood or when their walls lose their strength. Chronic venous insufficiency is an important factor. The condition is hereditary and manifests with functional disorders of the veins and their valves.
The venous insufficiency is usually combined with an inactive lifestyle (not using the muscle pump) and hormonal changes in pregnancy. The consequence of this situation is a stasis of blood in the veins of the lower extremities due to a disturbed function of valves. The blood pours through the insufficient valves from the deep system to the surface. The surface subcutaneous veins are unable to handle such overload and the amount of blood causes their dilation. The situation can be worsened by repeated inflammations of the superficial veins (thrombophlebitis) that damage the venous walls and reduce their mechanical strength thus making the varicose formation more likely. Another causative factor may be the deep vein thrombosis, which means development of a blood clot in the deep venous system. Such blood clot decreases the blood flow through the deep veins with compensatory increase of blood flow in the superficial venous system.
Varicose veins develop gradually as dilated bluish veins slightly raised above the skin surface of shanks and thighs. Large veins filled with blood have often crooked shape. The patient suffers from symptoms such as the feeling of heavy legs, leg pain, muscle cramps, and tingling sensations. In case of thrombophlebitis, the affected varicose vein turns reddish and painful on touch. Longer-term presence of varicose veins as a result of impaired outflow of blood from the lower extremities increases the risk of venous leg ulcers. The tissues of the lower limbs have decreased viability due to impaired blood outflow and the wound healing is decreased as well.
The varicose veins can be seen by the naked eye. When the patient is examined by an angiologist, the doctor usually uses the ultrasound of the veins to evaluate the condition of the deep venous system and the local blood flow.
The appropriate prevention of varicose veins is sufficient physical activity, weight loss in obese patients and wearing elastic compression stockings. It is advisable to avoid long standing and sitting with the legs down to prevent the blood stasis.
The patient can wear the compressive elastic stockings and use some medications known as venotonics. The drugs have anti-inflammatory effect, reinforce the venous walls and improve the drainage of blood from the lower extremities.
There is also the possibility of a surgical treatment when the affected superficial veins are removed (there are more surgical methods). Before such intervention, it is essential to evaluate the condition of the deep vein system by ultrasonography. In case of removal of the superficial veins, the deep system must be able to drain the venous blood.