Causes and Signs of Venous Thromboembolism

The blood clots, or thromboses, can form in any vein of the body, and if these clots break loose, they can cause an embolism. An embolism occurs when the thrombus lodges in the venous system of another organ, causing a disruption in blood flow. This phenomenon is referred to as venous thromboembolism (VTE), and since blood clots often remain undetected, their frequency is difficult to determine. Estimates suggest that there are 80-180 cases per 100,000 people each year.

Venous thromboembolism affects not only a narrow age group but encompasses a wide spectrum and can indicate serious underlying diseases or hereditary predispositions. Such issues can also be associated with other diseases, and their mortality rates are not negligible. Undetected cases can lead to late complications, making it important to be aware of the causes and symptoms of thrombosis.

Causes and Risk Factors of Venous Thromboembolism

There are several underlying causes for the appearance of venous thromboembolism, which can mostly be categorized into three main groups: damage to the vessel wall, venous blood stasis, and increased blood coagulability. These causes can play a role in the development of thrombosis in varying proportions, and the triggering factors are often linked to individual cases.

Hereditary thrombophilia, also known as familial thrombophilia, is the most common genetic cause, resulting from mutations in genes responsible for blood coagulation. A significant portion of the population in Hungary is affected by some form of inherited thrombophilia, which does not always lead to thrombosis. Risk factors include thrombosis occurring at a young age, multiple thromboses, blood clots forming in unusual locations, and family history. Additionally, the most common genetic abnormalities include the Leiden mutation, prothrombin gene polymorphism, and various protein deficiencies.

Acquired thrombophilia can be caused by several factors, such as previous surgeries, prolonged bed rest, chronic bowel diseases, or hematological issues. Age can also contribute to the development of thrombosis, as the risk increases in older adults. Besides these causes, it may happen that the triggering factors are never identified, or multiple causes may collectively contribute to the appearance of thrombosis.

Symptoms and Recognition of Venous Thromboembolism

Venous thromboembolism most commonly develops in the lower limbs, where typical signs of thrombosis include swelling, pain, skin tension, and warmth. Differences between the limbs, such as greater swelling in one leg, can serve as warning signs. In superficial vein thrombophlebitis, a painful, hard superficial vein is a clear indication of the problem, while in deep vein thrombosis, the affected limb is usually swollen and warm to the touch.

Abdominal thrombosis typically presents with digestive disturbances, nausea, and malaise, while pulmonary embolism, which is the most severe form of thromboembolism, can cause sudden onset of shortness of breath, coughing, and even hemoptysis. In the case of obstruction of the pulmonary vessels, symptoms can vary in severity, and the signs may appear a few days after thrombosis or may occur immediately.

It is important to be vigilant for signs of thrombosis, such as pain, swelling, redness, shortness of breath, and sudden onset of symptoms, all of which can serve as warning signs. If sudden, unilateral limb swelling or shortness of breath is experienced, it is crucial to seek medical attention immediately. The detachment of a blood clot and its manifestation as an embolism can be life-threatening, so the patient should be transported for medical care as soon as possible, preferably in a lying or sitting position until a diagnosis is made.