A blood clot in a vein. This is how phlebitis is defined, a disorder characterized by dull pain in the calf or thigh, or a feeling of heaviness in the leg. A situation not to be overlooked as the complications can be dramatic.
The venous network of the lower limbs comprises on the one hand a deep network made up of veins located in the muscles and which transport 90% of the venous blood, and on the other hand a superficial network of veins located under the skin.
A risk of embolism
If a clot forms in a superficial vein, so is phlebitis. On the other hand, if it develops in the deep network, we then speak of deep phlebitis. “The clot sticks to the wall of the calf vein“, notes Medicare. “When the organism fails to destroy it, it can extend towards the thigh, in the form of a floating part which can be detached easily. There is then a significant risk ofpulmonary embolism (responsible for 10 to 20,000 deaths each year in France, editor’s note), which makes deep phlebitis serious. The clot can also block the vein completely, causing pain and swelling in the affected leg.“
Watch out for hypercoagulable blood
Risky situations are those that slow the flow of blood from the veins to the heart. If the blood stagnates, the formation of clots is favored.
Any situation of immobility of the lower limbs also promotes coagulation: prolonged bed rest, wearing a cast, traveling for several hours by plane, train or car.
Pregnancy, obesity, smoking and advancing age promote the formation of a thrombus. Just like taking certain medications, such as hormonal contraception or corticosteroids.
Finally, phlebitis may be due to a genetic predisposition.
Signs to watch out for
If phlebitis can (sometimes) be asymptomatic, certain signs should prompt you to consult. We are talking here about calf pain (present in 6 out of 10 cases), a feeling of heaviness in the leg, edema and hardening of the calf or even a feeling of heat…
Specific exams
After examination, your attending physician may prescribe additional examinations. Like a blood test for D-dimers. They are the product of the degradation of fibrin, which is the main constituent of the clot. In the event of a positive result, the diagnosis of phlebitis should be confirmed by venous ultrasound. “This examination makes it possible to observe the quality of the venous circulation and to confirm the diagnosis.“, recalls Inserm.
What treatments?
At the stage of thrombosis, different anticoagulant treatments can be used. They do not destroy the clot but aim to prevent it from spreading.
There are also several ways to prevent the occurrence of phlebitis. The doctor can prescribe compression socks, stockings or tights. In all cases, certain lifestyle rules should be applied, such as practicing regular physical activity or fighting against overweight.
To note : During journeys of several hours, it is recommended, even in the absence of known risk, to perform regular leg movements or to walk as soon as possible.