The formation of a thrombus (blood clot) in an undamaged blood vessel. A thrombus that forms within an artery supplying the heart muscle (coronary thrombosis) is the usual cause of myocardial infarction. A thrombus in an artery of the brain (cerebral thrombosis) is a common cause of stroke. Thrombi sometimes form in veins, either just below the skin or in deeper veins (see thrombosis, deep vein).In arteries, thrombus formation may be encouraged by atherosclerosis, smoking, hypertension, and damage to blood vessel walls from arteritis and phlebitis.
An increased clotting tendency may occur in pregnancy, when using oral contraceptives, or through prolonged immobility.
An arterial thrombosis may cause no symptoms until blood flow is impaired.
Then, there is reduced tissue or organ function and sometimes severe pain.
Venous thrombosis may also cause pain and swelling.
Diagnosis is made by doppler ultrasound.
In some cases, angiography or venography may also be used.
Treatment may include anticoagulant drugs or thrombolytic drugs, nonsteroidal anti-inflammatory drugs, and antibiotic drugs.
In life-threatening cases, thrombectomy may be needed.
The formation of a blood clot within the circulatory system. It may form in the roughened vein wall in a varicosity, form around arteriosclerotic plaques, or result from trauma and surgery. The tendency rises with thick blood, age, obesity and in those once physically active and now sedentary.
The formation of a BLOOD CLOT within the vessels or heart during life. The process of clotting within the body depends upon the same factors as that of clotting of blood outside the body, involving the ?brinogen and calcium salts circulating in the blood, as well as blood PLATELETS. The indirect cause of thrombosis is usually some damage to the smooth lining of the blood vessels brought about by in?ammation, or the result of ATHEROMA, a chronic disease of the vessel walls. The blood is also specially prone to clot in certain general conditions such as ANAEMIA, the ill-health of wasting diseases like cancer, and in consequence of the poor circulation of old age.
Thrombosis may occur in the vessels of the brain and thus causes STROKE in people whose arteries are much diseased.
Thrombosis of a coronary artery of the heart is a very serious condition which affects, as a rule, middle-aged or elderly people.
(See also ARTERIES, DISEASES OF; COAGULATION; HEART, DISEASES OF – Coronary thrombosis; VEINS, DISEASES OF.)
A blood clot that may partially or wholly block the flow of blood through a blood vessel
n. a condition in which the blood changes from a liquid to a solid state within the cardiovascular system during life and produces a mass of coagulated blood (thrombus). Thrombosis may occur within a blood vessel in diseased states. Thrombosis in an artery obstructs the blood flow to the tissue it supplies: obstruction of an artery to the brain is one of the causes of a *stroke and thrombosis in an artery supplying the heart – *coronary thrombosis – results in a heart attack (see myocardial infarction). Thrombosis can also occur in a vein (deep vein thrombosis; see phlebothrombosis), and it may be associated with inflammation (see thrombophlebitis). The thrombus may become detached from its site of formation and carried in the blood to lodge in another part (see embolism).
formation of a thrombus or blood clot.
the presence of thrombosis in the dural venous sinuses, which drain blood from the brain. Symptoms may include headache, abnormal vision, any of the symptoms of stroke (such as weakness of the face and limbs on one side of the body), and seizures. Treatment is with anticoagulants.... cerebral venous sinus thrombosis
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