Thrombosis occurs when blood clots block your blood vessels. There are 2 main types of thrombosis:
Venous thrombosis is when the blood clot blocks a vein. Veins carry blood from the body back into the heart.
Arterial thrombosis is when the blood clot blocks an artery. Arteries carry oxygen-rich blood away from the heart to the body.
Venous thrombosis may be caused by:
Disease or injury to the leg veins
Not being able to move around (immobility) for any reason
A broken bone (fracture)
Inherited disorders, or a greater likelihood of having a certain disorder based on your genes
Autoimmune disorders that make it more likely your blood will clot
Medicines that increase your risk of clotting(such as certain birth control medicines
Arterial thrombosis may be caused by a hardening of the arteries (atherosclerosis). This happens when fatty or calcium deposits cause artery walls to thicken. This can lead to a buildup of fatty material (plaque) in the artery walls. This plaque can suddenly burst (rupture), followed by a blood clot.
Arterial thrombosis can occur in the arteries that supply blood to the heart muscle (coronary arteries). This can lead to a heart attack. When arterial thrombosis occurs in a blood vessel in the brain, it can lead to a stroke.
Many of the risk factors for venous and arterial thrombosis are the same.
Risk factors for venous thrombosis may include:
A family history of a blood clot in a vein deep in the body (deep vein thrombosis or DVT)
A history of DVT
Hormone therapy or birth control pills
Injury to a vein, such as from surgery, a broken bone, or other trauma
Lack of movement, such as after surgery or on a long trip
Inherited blood clotting disorders
A central venous catheter
Being overweight or obese
Some health conditions, such as cancer, heart disease, lung disease, or Crohn's disease
Risk factors for arterial thrombosis may include:
High blood pressure
Lack of activity and obesity
Family history of arterial thrombosis
Symptoms may vary a bit for each person. Symptoms may include:
Pain in one leg, usually the calf or inner thigh
Swelling in the leg or arm
Numbness or weakness on one side of the body
Sudden change in your mental state
Cold arm or leg
The symptoms of thrombosis may look like other blood disorders or health problems. Always see your healthcare provider for a diagnosis.
Your healthcare provider will ask about your health history and give you a physical exam. Other tests may include:
Ultrasound. This test uses sound waves to check the blood flow in your arteries and veins.
Blood tests. These may include tests to see how well your blood can clot.
Venography. For this test, a dye is injected into your veins. Then X-rays are taken to show blood flow and look for clots. The dye makes your veins easier to see on the X-rays.
MRI, MRA or CT scan. The imaging procedure that is used will depend on the type of blood clot you have and where it is located.
Angiography. This imaging test uses a contrast dye to look at the blood vessels.
Treatment may include:
Blood-thinning medicines (anticoagulants)
Thin tubes (catheters)