====Portal vein thrombosis====
Portal vein thrombosis is a form of venous thrombosis affecting the hepatic portal vein, which can lead to portal hypertension and reduction of the blood supply to the liver. It usually has a pathological cause such as such as [[pancreatitis]], [[cirrhosis]], [[diverticulitis]] or [[cholangiocarcinoma]].
====Renal vein thrombosis====
Renal vein thrombosis is the obstruction of the [[renal vein]] by a thrombus. This tends to lead to reduced drainage from the kidney. [[Anticoagulation]] therapy is the treatment of choice.
====Jugular vein thrombosis====
====Budd-Chiari syndrome====
Budd-Chiari syndrome is the blockage of the [[hepatic vein]] or the [[inferior vena cava]]. This form of thrombosis presents with [[abdominal pain]], [[ascites]] and [[hepatomegaly]]. Treatment varies between therapy and surgical intervention by the use of [[shunt]]s.
====Paget-Schroetter disease====
{{main|Paget-Schroetter disease}}Paget-Schroetter disease is the obstruction of an [[upper extremity]] vein (such as the [[axillary vein]] or [[subclavian vein]]) by a thrombus. The condition usually comes to light after vigorous exercise and usually presents in younger, otherwise healthy people. Men are affected more than women.
====Cerebral venous sinus thrombosis====
Cerebral venous sinus thrombosis (CVST) is a rare form of [[stroke]] which results from the blockage of the dural venous sinuses by a thrombus. 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]]. The diagnosis is usually made with a Computed Tomography|CT or Magnetic Resonance Imaging|MRI scan. The majority of persons affected make a full recovery. The [[mortality rate]] is 4.3%.<ref name="Canhao">{{cite journal | last=Canhão | first=P | coauthors=Ferro JM, Lindgren AG et al. | title=Causes and predictors of death in cerebral venous thrombosis | volume=36 | issue=8 | pages=1720–1725 | journal=Stroke | date=August 2005 | url=http://stroke.ahajournals.org/cgi/content/full/36/8/1720 | pmid=16002765 | doi=10.1161/01.STR.0000173152.84438.1c}}</ref>
===Arterial thrombosis===
Arterial thrombosis is the formation of a thrombus within an artery. In most cases, arterial thrombosis follows rupture of atheroma, and is therefore referred to as ''atherothrombosis''.
Another common cause of arterial thrombosis is atrial fibrillation, which causes disturbed blood flow. In addition, it is well known that the direct current cardioversion of atrial fibrillation carries a great risk of thromboembolism, especially if persisting more than 48 hours. Thromboembolism strikes approximately 5% of cases not receiving anticoagulant therapy. The mechanism and pathogenesis of thromboembolism after cardioversion is not completely understood.<ref>{{cite journal |author=Hatzinikolaou-Kotsakou E, Kartasis Z, Tziakas D, ''et al.'' |title=Clotting state after cardioversion of atrial fibrillation: a haemostasis index could detect the relationship with the arrhythmia duration |journal=Thromb J |volume=3 |issue=1 |pages=2 |year=2005 |month=March |pmid=15748296 |pmc=555849 |doi=10.1186/1477-9560-3-2 |url=}}</ref>
Arterial thrombosis can embolize and is a major cause of [[arterial embolism]], potentially causing [[infarction]] of almost any organ in the body.
====[[Stroke]]====A stroke is the rapid decline of brain function due to a disturbance in the supply of blood to the brain. This can be due to [[ischemia]], thrombus, embolus (a lodged particle) or hemorrhage (a bleed). In thrombotic stroke, a thrombus (blood clot) usually forms around [[atherosclerotic]] plaques. Since blockage of the artery is gradual, onset of symptomatic thrombotic strokes is slower. Thrombotic stroke can be divided into two categories—large vessel disease and small vessel disease. The former affects vessels such as the internal carotids, Vertebral artery|vertebral and the circle of Willis. The latter can affect smaller vessels such as the branches of the circle of Willis.
====Myocardial infarction====
Myocardial infarction (MI) is caused by an infarct (death of tissue due to ischemia), often due to the obstruction of a [[coronary artery]] by a thrombus. MI can quickly become fatal if emergency medical treatment is not received promptly. If diagnosed within 12 hours of the initial episode (attack) then [[thrombolysis|thrombolytic therapy]] is initiated.