Several factors may increase the risk of developing deep vein thrombosis, especially of the lower limbs.
1) Surgery:
Patients undergoing surgeries in the pelvic region and lower limbs present a high risk of thrombus formation in the lower limbs. The effect of anesthetics, the manipulation of blood vessels and underlying tissues during the surgical procedure, and the prolonged time without getting up postoperatively make surgery an event with a high risk of deep vein thrombosis.
* As we walk, the impact of the feet on the floor and the contraction of the muscles, especially the calf, help to push the blood in the veins of the legs upwards toward the heart. Staying lying down for a long time favors blood stasis in the lower limbs, especially for those who suffer from venous insufficiency.
2) Trauma:
For reasons similar to surgery, large traumatisms are also important risk factors for deep venous thrombosis, both because of the impact on the blood vessels and the time that the person is immobilized in the bed after the accident.
3) Stay seated on long trips:
Long trips, usually longer than 8 hours, may facilitate the onset of deep vein thrombosis, especially in individuals with other risk factors such as obesity, varicose veins, smoking, pregnancy, etc.
Have you noticed how swollen your feet are and the shoe gets harder to wear after a long plane ride? Staying seated for many hours, with legs bent, hinders the return of blood to the heart, favoring stasis and, consequently, the formation of thrombi.
4) Cancer:
There are malignant tumors that produce substances that increase the chance of blood clotting, favoring the formation of thrombi.
5) Heart failure:
Individuals with heart failure have a weak heart, with difficulty to pump blood to the whole body, which leads to blood stagnation in the lower limbs and favors the formation of clots.
6) Pregnancy:
Hormonal changes increase the coagulation capacity of pregnant women. In addition, as the uterus grows, the vena cava is compressed, which hinders the flow of blood from the veins of the lower limbs. Pregnant women are 5 times more likely to develop thrombosis than women who are not pregnant at the same age.
7) Thrombophilia:
Blood diseases that make deregulate the coagulation system, creating a state of hypercoagulability and great risk of thrombus formation. However, although they are a strong risk factor for thrombosis, thrombophilias are uncommon pathologies. Among the most frequent thrombophilias, the following stand out:
- Factor V Mutation of Leiden;
- Prothrombin gene gene mutation;
- Deficiency of protein S;
- Protein C deficiency;
- Antithrombin deficiency;
- Dysfibrinogenemia;
- Anti-phospholipid antibody.
In addition to those previously mentioned, there are several other risk factors for deep venous thrombosis, including:
- Obesity;
- Genetic predisposition;
- Dehydration;
- Difficulty of ambulation;
- Varicose veins;
- Smoking;
- Use of hormonal contraceptives or hormone therapy;
- Age above 60 years;
- Nephrotic syndrome;
- Use of certain medications (such as tamoxifen, erythropoietin, thalidomide, and menopausal hormone replacement);
- Family history of thrombosis;
- Polycythemia vera;
- Essential thrombocytopenia;
- Inflammatory bowel disease;
- Use of central venous catheter in the femoral vein.
If deep vein thrombosis is suspected, a physician should be consulted. He will be able to evaluate in detail, through anamnesis, physical examination and eventual complementary tests, what his correct diagnosis is, guide him and prescribe the best treatment, case by case.
