Thrombosis is the formation of a blood clot in a blood vessel. This blood clot obstructs the flow of blood, i.e., the blood gathers in front of the narrowed vessel and no longer flows through it as it should. In principle, the coagulation of blood is an important process – otherwise we would bleed to death every time we cut ourselves. However, blood clots in blood vessels are problematic, as they can partially or completely hinder the blood flow.
Thromboses can occur in any of the body’s arteries or veins. Arterial thrombosis can cause heart attacks, strokes and blocked arteries in the legs (“peripheral arterial disease”).
Vein thrombosis is not uncommon and is divided into two variants: superficial and deep vein thrombosis.
Superficial phlebitis (superficial thrombophlebitis) is frequently caused when a vein is damaged, frequently from varicose veins. The inflamed vein usually feels sore and like a thick, hard cord under the skin. In the absence of varicose veins, superficial phlebitis indicates the existence of another serious disease and must also be treated.
Superficial phlebitisis is neither rare nor harmless. Left untreated, it can lead to deep vein thrombosis, which, in turn, can cause a pulmonary embolism. Those who have suffered from superficial phlebitis tend to develop new thromboses. Treatment is usually simple: compression (compression stockings, compression bandaging), cooling (cold compresses, bandages with heparin ointment) and movement.
Although each patient’s situation is different, veins affected by phlebitis are usually removed through smaller incisions, followed by anticoagulation therapy with drugs. To avoid a superficial thrombosis – which often occurs in hot weather – and further complications, we recommend treating varicose veins early on.
Deep vein thrombosis (DVT) occurs in the deeper veins inside the leg and must be treated immediately to reduce the risk of a pulmonary embolism. Patients who suspect they have thrombosis should always come to the clinic immediately – or go to one of our colleagues or to a hospital emergency room. Treatment includes medication, compression stockings or an operation.
Thrombosis is quite easy to recognize: The affected leg swells significantly for no apparent reason, it is sore, unusually warm, lacks sensation and the skin is obviously tight. The leg may sometimes be bluish or reddish, indicating a blood clot. The symptoms ease when lying down, and worsen when standing or walking. Do not wait if you are suffering from these symptoms: seek immediate medical attention, so a doctor can perform a quick ultrasound, for example, to determine if you have a thrombosis!
Untreated leg (and pelvis) vein thrombosis can lead to a life-threatening pulmonary embolism, which can occur when a blood vessel in your lung becomes blocked by a thrombus that travels to your lungs from another part of your body, usually a leg.
Causes and risk factors
Major operations, obesity, blood coagulation disorders, cancer, pregnancy, the birth control pill (especially when combined with nicotine) and physical inactivity (prolonged sitting – for example during long car trips or a long flight – being bedridden or wearing a leg cast) all increase the risk of thrombosis. This is because the major “muscle pump” in the leg is inactive. When we move about normally, the activated muscles press on the blood vessels and support the flow of blood. If this function does not take place because of a lack of movement, the blood flows too slowly, fostering a thrombosis. The body can usually dissolve smaller clots on its own; however, the heavier and older a person is, the harder it becomes for his or her body to do this. A small coagulum can become a blood clot, which occludes the vessel and impedes the necessary blood flow.
Untreated varicose veins are one of the major causes of thrombosis. We therefore often recommend, – especially with people who are more at risk because of heart problems, for example those who suffer from cardiac arrhythmia – to prophylactically treat varicose veins.
In general, we recommend that patients keep normal daily activities after deep vein thrombosis. Please consult us before engaging in any sports or putting undue pressure on the leg! A bit of movement can help initially but is not mandatory.
In addition to blood-thinning medications, we also prescribe customized compression tights (not to be confused with support stockings!). The tights provide the veins with a slight resistance so that they do not “stretch out” again, but become tighter. This supports the flow of blood, which helps prevent further clots from forming. The compression stocking must fit well, i.e., it should not be too tight or too loose and it must be used consistently. Experimental treatment without the direct supervision of a qualified physician in the case of a thrombosis is not effective or recommended, and most certainly not when a patient has acute symptoms with a high risk of complications! A compression bandage can be very useful – if it is applied by professionals! It can also decongest the affected area. An improper fit has the opposite effect and increases congestion and the risk of complications.
When initially treating larger deep vein thrombosis, infusions drugs are used to try to dissolve the blood clot (thrombolysis). We rarely recommend an operation for removing the blood clot. In extensive venous thrombosis, however, this can be a useful intervention; gentle and minimally invasive treatment methods are now available so the side effects of such an operation are no longer as great and are easier to predict.