What is thrombosis?

Thrombosis occurs when clots obstruct or block veins (blood vessels that carry blood from the body back into the heart) or arteries (blood vessels that carry oxygenated blood away from the heart to the body). Venous thrombosis is when the blood clot obstructs a vein, and arterial thrombosis is when the blood clot obstructs an artery.

What causes thrombosis?

Venous thrombosis may be the result of the following:

  • Disease or injury to the veins in the legs

  • Immobility for any reason

  • Fracture

  • Certain medications

  • Obesity

  • Inherited disorders or inherited predisposition

  • Autoimmune disorders that predispose to clotting

  • Medications, such as certain contraceptives, that increase the risk of clotting 

Pooling (stasis) of blood in the legs and subsequent clotting can result in varicose veins. Clots in the legs may break loose and travel to the lungs, causing pulmonary clots that can result in respiratory distress, pain, and in extreme cases, death.

Arterial thrombosis may be the result of arteriosclerosis, which involves hardening of the arteries where fatty or calcium deposits cause the arterial walls to thicken. This can lead to plaque instability and risk for rupture followed by thrombus.

When arterial thrombosis occurs in the coronary arteries (arteries that branch from the aorta to provide blood to the heart muscle), it can lead to heart attacks. When arterial thrombosis occurs in the cerebral (brain) circulation, it can lead to strokes or lack of oxygen to other organs.

Risk factors for arterial thrombosis may include:

  • Smoking

  • Diabetes

  • High blood pressure

  • High cholesterol

  • Lack of activity and obesity

  • Poor diet

  • Family history of arterial thrombosis 

What are the symptoms of thrombosis?

The following are the most common symptoms of thrombosis. However, each individual may experience symptoms differently. Symptoms may include:

  • Pain isolated to one leg (usually the calf or inner thigh)

  • Swelling in the extremity

  • Chest pain

  • Numbness or weakness on one side of the body

  • Acute mental status changes 

The symptoms of thrombosis may resemble other blood disorders or medical problems. Always consult your doctor for a diagnosis.

How is thrombosis diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for thrombosis may include venous and arterial ultrasounds and blood tests including hypercoagulability panels. Dye injection with angiography and catheterization may also be used, as well as MRI/MRA and CT. The diagnostic procedure advised depends on the type of thrombus--venous or arterial--and the location. 

Treatment for thrombosis

Specific treatment for thrombosis will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent and type of thrombosis

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the disease

  • Your opinion or preference

Treatment may include:

  • Anticoagulant medications, such as coumadin and heparin

  • Catheters (to expand the width, or lumen, of involved vessels)

  • Stent placement

  • Medications, such as antiplatelets, tissue plasminogen activator (t-PA), and/or enzymes, such as streptokinase (to dissolve clots)

Other treatments may be advised in your particular situation and will be reviewed in detail with you by your doctor.