Thrombosis most often arises in veins of legs.

Thrombosis is the obstruction of vessels caused by blood clot. Thrombosis most often arises in veins of legs. Important symptoms of thrombosis include hypostasis, pain and reddening or cyanosis of skin. Thrombosis is dangerous that blood clot can come off and get to other bodies.

Thrombosis: reasons and risk factors

Thrombosis is the blood clot which is formed in blood vessels. Generally they can have three reasons:

Damages, diseases, deposits on a vascular wall or narrowing of blood vessels because of mechanical pressure from the outside (for example, hems, tumors).

Slow speed of a blood-groove: it can be caused patholologically by expanded veins, gravity or an insufficient muscle tension.

The increased tendency of blood to formation of blood clots (Thrombophilia): at diseases of a coagulant system of blood, serious general diseases (cancer, autoimmune diseases), owing to smoking or at intake of some medicines as side effect.

Thrombosis at a varicosity

The varicosity is expanded blood vessels.
At a varicosity blood flows more slowly, and natural valves of veins (venous valves) cease to function properly. It increases risk of thrombosis. 

The most important risk factors

There is a number of the factors promoting a venous thromboembolism that is to formation of blood clots and their moving to a blood stream where they block a vessel.

Risk factors are:

Heart failure, ciliary arrhythmia or atrial flutters.
Severe injury.
Heart attack (in the last three months).
Injury of a spinal cord.
Previous venous thromboembolism (for example, thromboembolism of a pulmonary artery).

Thrombosis: diagnostics and inspection

In general superficial thrombosis is characterized by heavier symptoms and therefore it is easier to diagnose it.

Blood test

In addition to visualization, blood test is also important for identification of suspicion of thrombosis. It assumes search of decomposition products of blood clots, so-called D-dimerov.

Visual diagnostics

Ultrasonography can show obstruction of veins.
At a flebografiya blood vessels can be seen on a x-ray film. This procedure well is suitable for diagnostics of a deep vein thrombosis.
The Computer Tomography (CT) is widely used in vascular medicine.
In some cases vessels are visualized after administration of contrast medium by means of magnetic resonance imaging.