Disorders of the leg veins arise as a result of a disturbance in blood flow and can manifest themselves in a variety of ways: from minor impairments right through to illnesses that can be life-threatening if not recognized.

Spider veins
When the smallest veins in the uppermost layer of the skin distend and take on the appearance of a fine network on the surface of the legs, we refer to these as spider veins.
The word “spider” refers to the typical web-like appearance of these superficial venules. In themselves, spider veins on the thighs, calves or ankles are more of a cosmetic issue than an immediate cause for concern. They can, however, also be an indication of weakness of the connective tissue or of a serious venous disorder.
Thrombosis
Thromboses arise as a result of a clotting disorder of the blood. When the blood suddenly clots in the vascular system, a thrombus can form on the vessel wall. This kind of thrombus usually forms in the veins – in particular in the deep leg veins. These deposits constrict the vessels or can even block them completely.
The blood can no longer flow optimally through the veins to the heart. This is then referred to as a deep vein thrombosis. The symptoms can vary widely, and do not have to all occur together. That is why a deep venous thrombosis is not always easy to recognize.
Look out for the following warning signs on your legs:
- swelling
- pain on exertion, in particular while walking, standing or sitting
- discoloration or glossiness of the skin (red or blue)
- feeling of tension
- a warm sensation on the affected limb
- sudden appearance of veins on the surface (e.g. a “warning vein” over the shin bone)
When a thrombus forms in the superficial veins, this is usually accompanied by inflammation. One possible symptom of a superficial vein thrombosis is hardening or reddening of the affected area. Tenderness may also arise.
If you suspect the presence of a thrombosis, you should consult a physician immediately! Often a thrombosis will initially not be accompanied by any symptoms at all, and therefore not be recognized in a timely manner. A pulmonary embolism could potentially form.
Varicose veins (varices)
Varicose veins usually run in the family. They are caused by an inherited weakness in the vein walls. If you suffer from varicose veins, it is possible to limit or delay their spread through effective treatment measures such as for example, compression therapy. This condition cannot, unfortunately, be cured by medication, however, these can be a valuable supplement to other therapeutic measures.
A varicose vein (varix) refers to a distended vein in which the venous valves have ceased to function properly. As a result, the blood can no longer be optimally transported back to the heart. The blood collects in the legs due to gravity, thereby leading to blood stagnation.
The pressure in the veins increases, which causes the vein walls to stretch and the veins to bulge out. The distended vein becomes tortuous and knotty. It may become visible on the surface of the skin and produce tangible bulge.
Fig. 1 Normal vein: The venous valves prevent the blood from returning into the legs
Fig. 2 Varicose veins: Due to the distension of the vein, backflow of the blood through the venous valves cannot be prevented
Varicose veins should never be regarded as a purely cosmetic problem. If left untreated, they can cause severe leg complaints and disorders, for example inflammation of the veins or tissue damage. Early recognition can help to avoid such complications. Good to know
It is possible to distinguish between two types of varicose veins:
- Primary varicosis: Approx. 80 % of all varicose vein disorders. It is caused by a hereditary weakness of the vein walls or insufficiency of the venous valves.
- Secondary varicosis: Usually develops after a deep vein thrombosis. It is the result of many years of strain on the superficial veins due to blood stagnation.