Thromb: From 1 Different Sources
(thrombo-) combining form denoting 1. a blood clot (thrombus). 2. thrombosis. 3. blood platelets.
A blood clot that may partially or wholly block the flow of blood through a blood vessel... thrombosis
See HEART, DISEASES OF.... coronary thrombosis
Also known as Buerger’s disease, this is an in?ammatory disease involving the blood vessels and nerves of the limbs, particularly the lower limbs. TOBACCO is an important cause. Pain is the outstanding symptom, accompanied by pallor of the affected part; intermittent CLAUDICATION caused by a reduction in blood supply is common. Sooner or later ulceration and GANGRENE tend to develop in the feet or hands when AMPUTATION of the affected part may be necessary. There is no speci?c treatment, but, if seen in the early stages, considerable relief may be given to the patient. Regular walking exercise is helpful and affected individuals should not smoke.... thromboangiitis obliterans
See PLATELETS.... thrombocyte
A fall in the number of PLATELETS (thrombocytes) in the blood caused by failure of production or excessive destruction of platelets. The result is bleeding into the skin (PURPURA), serious bleeding after injury and spontaneous bruising. (See also IDIOPATHIC THROMBOCYTOPENIC PURPURA (ITP).)... thrombocytopenia
In?ammation of the veins combined with clot formation. (See BLOOD CLOT; VEINS, DISEASES OF.)... thrombophlebitis
A BLOOD CLOT. Usually describing the formation of a clot within a vessel obstructing the ?ow of blood, but it can also describe blood which has escaped from a damaged vessel and clotted in the surrounding tissue. (See also THROMBOSIS.)... thrombus
See COAGULATION.... thrombin
The breakdown of a BLOOD CLOT by enzymic activity (see ENZYME). Naturally occurring enzymes limit the enlargement of clots, and drugs – for example, STREPTOKINASE – may be given to ‘dissolve’ clots (e.g. following a coronary THROMBOSIS – see under HEART, DISEASES OF). The drug needs to be given within 6–12 hours to be e?ective in reducing the death rate, so prompt diagnosis and transfer to hospital is essential: a short ‘door-to-needle’ time. An unwanted e?ect may be increased risk of bleeding, especially in the elderly. It has been used in trials in patients with PULMONARY EMBOLISM and with peripheral arterial disease, but its value in these conditions is uncertain.... thrombolysis
Also known as thrombokinase, this is an ENZYME formed in the preliminary stages of the COAGULATION of blood. It converts the inactive PROTHROMBIN into the enzyme THROMBIN.... thromboplastin
A substance produced in the blood PLATELETS which induces aggregation of platelets and thereby THROMBOSIS. It is also a vasoconstrictor (a substance that causes the constriction of blood vessels).... thromboxane
See thrombosis, deep vein.... deep vein thrombosis
The removal of a thrombus that is blocking a blood vessel. It is performed as an emergency procedure if a major artery is blocked, or as a precautionary measure if there is a risk of an embolus breaking off. Before surgery, the site of the thrombus is established by angiography and the patient may be given anticoagulant drugs.... thrombectomy
A tendency for blood to clot too readily due to an inherited abnormality in proteins such as factor V. It may not be recognized until specific circumstances such as injury or air travel cause symptoms or signs. (See also thrombosis, deep vein.)... thrombophilia
See THROMBOSIS; VEINS, DISEASES OF.... deep vein thrombosis (dvt)
Sometimes described as thrombocytopenia, this is an autoimmune disorder in which blood PLATELETS are destroyed. This disturbs the blood’s coagulative properties (see COAGULATION) and spontaneous bleeding (PURPURA) occurs into the skin. The disease may be acute in children but most recover without treatment. Adults may develop a more serious, chronic variety which requires treatment with CORTICOSTEROIDS and sometimes SPLENECTOMY. Should the disease persist despite these treatments, intravenous immunoglobulin or immunosuppressive drugs (see IMMUNOSUPPRESSION) are worth trying. Should the bleeding be or become life-threatening, concentrates of platelets should be administered.... idiopathic thrombocytopenic purpura (itp)
See THROMBOCYTOPENIA.... thrombocytopenic
These are compounds with the property of breaking up blood clots in the circulatory system (see BLOOD CLOT; THROMBUS; THROMBOSIS; FIBRINOLYTIC DRUGS).... thrombolytic agents
(ITP) An autoimmune disorder in which platelets are destroyed, leading to bleeding beneath the skin (see purpura).... idiopathic thrombocytopaenic purpura
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
(ITP) an *autoimmune disease in which platelets are destroyed, leading to spontaneous bruising (see purpura). Acute ITP is a relatively mild disease of children, who usually recover without treatment. A chronic form of the disease, typically affecting adults, is more serious, requiring treatment with corticosteroids or, if there is no response, with splenectomy. If both fail, immunosuppressant drugs may be effective. Platelet concentrates are used for life-threatening bleeding.... idiopathic thrombocytopenic purpura
see thrombophilia.... inherited thrombophilias
n. a hereditary blood disease in which the function of the *platelets is defective although they are present in normal numbers. The manifestations are identical to those of thrombocytopenic *purpura.... thrombasthenia
n. a disease in which there is an abnormal proliferation of the cells that produce blood *platelets (*megakaryocytes), leading to an increased number of platelets in the blood. This may result in an increased tendency to form clots within blood vessels (thrombosis); alternatively the function of the platelets may be abnormal, leading to an increased tendency to bleed. Treatment is by radiotherapy, *cytotoxic drugs, *interferon, or drugs that inhibit *megakaryocyte maturation.... thrombocythaemia
n. an increase in the number of *platelets in the blood. It may occur in a variety of diseases, including chronic infections, cancers, and certain blood diseases and is likely to cause an increased tendency to form blood clots within vessels (thrombosis).... thrombocytosis
n. see endarterectomy.... thromboendarterectomy
n. thrombosis complicating *endarteritis, seen in temporal *arteritis, *polyarteritis nodosa, and syphilis. It may cause death of part of the organ supplied by the affected artery.... thromboendarteritis
n. see thromboplastin.... thrombokinase
adj. describing an agent that breaks up blood clots (thrombi). Thrombolytic drugs are used to unblock arteries in the treatment of myocardial infarction. See fibrinolytic; tissue-type plasminogen activator.... thrombolytic
n. the process of blood *platelet production. Platelets are formed as fragments of cytoplasm shed from giant cells (*megakaryocytes) in the bone marrow by a budding process.... thrombopoiesis
n. measures taken to reduce the risk of venous *thrombosis and therefore avoid *thromboembolism during hospitalization. Techniques include tight support stockings to minimize venous stasis and subcutaneous injections of a *low-molecular-weight heparin to thin the blood.... thromboprophylaxis
the formation of thrombi in arterioles and capillaries, leading to haemolytic anaemia and *thrombocytopenia. The term encompasses primary *haemolytic uraemic syndrome and *thrombotic thrombocytopenic purpura, as well as the microangiopathies that can complicate pregnancy (pregnancy-related haemolytic uraemic syndrome, *HELLP syndrome), *malignant hypertension, *scleroderma, *antiphospholipid antibody syndrome, organ transplantation, and cancer.... thrombotic microangiopathy
(TTP) a rare disorder of coagulation caused by deficiency or inhibition of *ADAMTS13, a protein that is responsible for breaking down von Willebrand factor (see von Willebrand’s disease). This results in haemolytic *anaemia, *thrombocytopenia, and fluctuating neurological abnormalities. It is treated by *plasmapheresis.... thrombotic thrombocytopenic purpura
(VTE) the formation of a blood clot in a vein, which may become detached and lodged elsewhere. It includes deep vein thrombosis (see phlebothrombosis) and *pulmonary embolism. VTE is a leading direct cause of maternal death (see maternal mortality rate). See also thromboembolism.... venous thromboembolism
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