Common forms Superficial venous thromboses cause discomfort but generally not serious consequences, as do the deep vein thromboses (DVTs) that form in the deep veins of the legs or in the pelvic veins. Nevertheless, they can progress to the deep veins through the perforator veins or, they can be responsible for a lung embolism mainly if the head of the clot is poorly attached to the vein wall and is situated near the sapheno-femoral junction. When a blood clot breaks loose and travels in the blood, this is called a thromboembolism. The abbreviation DVT/PE refers to a VTE where a deep vein thrombosis (DVT) has moved to the lungs (PE or pulmonary embolism). Since the veins return blood to the heart, if a piece of a blood clot formed in a vein breaks off it can be transported to the right side of the heart, and from there into the lungs. A piece of thrombus that is transported in this way is an embolus: the process of forming a thrombus that becomes embolic is called a thromboembolism. An embolism that lodges in the lungs is a pulmonary embolism (PE). A pulmonary embolism is a very serious condition that can be fatal depending on the dimensions of the embolus. Rare forms While venous thrombosis of the legs is the most common form, venous thrombosis may occur in other veins. These may have particular specific risk factors: * Cerebral venous sinus thrombosis, cavernous sinus thrombosis and jugular vein thrombosis: thrombosis of the veins of the brain and head * Central retinal vein occlusion and branch retinal vein occlusion: despite the name these conditions have much more in common with arterial thrombosis and are not treated with anticoagulants * Paget–Schroetter disease: thrombosis of the veins of the arms (axillary and subclavian veins) * Budd-Chiari syndrome (thrombosis of the hepatic vein) * Thrombosis of the hepatic portal system, also known as splanchnic venous thrombosis: * Thrombosis of the superior mesenteric vein, which may cause mesenteric ischemia (insufficient blood flow to the intestine) * Portal vein thrombosis * Thrombosis of the splenic vein * Renal vein thrombosis (thrombosis of the veins of the kidneys) * Ovarian vein thrombosis Parodoxical embolism Systemic embolism of venous origin can occur in patients with an atrial or ventricular septal defect, or an arteriovenous connection in the lung, through which an embolus may pass into the arterial system. Such an event is termed a paradoxical embolism. When this affects the blood vessels of the brain it can cause stroke.
complications of Klinefelter syndrome
complications of Kallmann syndrome
onset of Kallmann syndrome
medical cause of Precocious puberty
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complications of XYY syndrome
symptoms of Congenital adrenal hyperplasia
complications of Turner syndrome