Blood clots most commonly occur in the veins of the lower legs and pelvis (known as deep vein thrombosis or DVT) and the lungs (known as pulmonary embolism or PE). However, thrombosis may occur rarely in unusual sites of the body which can present unique challenges to treatment. For instance, clots can form in the nervous system, abdomen, or organs. Below is a list of examples of unusual thrombosis disorders.

                                                                              

CEREBRAL VEIN THROMBOSIS

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Cerebral vein thrombosis (CVT) is very rare – under 1% of all strokes are due to it. Interestingly, it is more common in women than men – by 3 times. The recommended treatment for CVT is immediate blood-thinner (anticoagulant) medication. Importantly, the chances of another CVT after already having one is low.

                                                                              

RETINAL VEIN THROMBOSIS

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Retinal vein thrombosis, known as retinal vein occlusion (RVO), can cause blindness, double vision, or no symptoms at all. This condition may affect millions of people over 80 every year. Risk factors for RVO include hypertension, diabetes, smoking, and obesity. Treatment options are very limited for patients with RVO as blood-thinning medication doesn’t seem to help. Instead, patients are given other kinds of medication such as steroids.

                                                                              

UPPER EXTREMITY THROMBOSIS (UEDVT)

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Blood clots in the deep veins of the arms is rare – only 5% of DVTs in normal people. However, in hospital up to 50% of people with DVTs have them in their arms. Almost all blood clots in the arms are caused by the presence of catheters. Patients that develop blood clots due to catheters are usually put on blood-thinning medication while the catheter is in place and for a period afterwards.

                                                                              

HEPATIC VEIN THROMBOSIS

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Hepatic vein thrombosis is when blood clots form in the veins of the liver. This is known as Budd-Chiari Syndrome and can result in liver failure and other forms of liver disease. Blood-thinning medication (anticoagulants) are recommended to treat this form of thrombosis.

Blood clots can also form in the “portal venous system” which is a group of large veins that allow blood to leave major organs including the liver and spleen. This is known by the overarching term “Splanchnic vein thrombosis”.