A blood clot can occur under two conditions.
Vascular surgeon Vladimir Smovzhenko named three conditions under which it can occur blood clot in blood vessels.
This requires the coincidence of three characteristics, which are called a triad Vihrova (the theory of the formation of a blood clot).
A thrombus occurs when the reduction of blood flow velocity in Vienna, violation of fluidity of the blood, which becomes thick and the damage of the inner wall of a venous vessel.
A clot is dangerous because it can break away and clog the pulmonary artery thromboembolism. Because of this, people may die. If small clots break off and fall into the pulmonary artery. Consequently, the claimed shortness of breath, chest pain.