A vein occlusion occurs when a vein in the body becomes blocked, clogged, or too narrow to allow blood to flow through easily. As a result, deoxygenated blood cannot return to the heart to continue normal circulation. Blood can back up in a vein and cause swelling, pain, and dysfunction in nearby organs and tissues. The most common site of vein occlusion is the retina of the eye, but any vein in the body can potentially be affected. Treatment depends on the location and severity of the obstruction, but common techniques include taking blood-thinning medications and undergoing surgical procedures.
Many different factors can increase a person's risk of developing a vein occlusion. Atherosclerosis, a condition that causes cholesterol to build up and harden in blood vessels, is a major risk factor. People who have diabetes, high blood pressure, poor diets, and sedentary lifestyles are generally more susceptible to atherosclerosis and occlusions in arteries and veins. Glaucoma significantly raises the risk of a retinal vein occlusion. In addition, some people are genetically predisposed to blood clotting disorders and circulation problems.
When a blood clot or another obstruction blocks a vein, blood begins to circulate backward. It reenters tissues and organs, which can lead to a number of symptoms. A vein occlusion in the ankle, for example, can cause the joint to quickly swell, become tender, and turn blue. A retinal vein occlusion may cause blurry or distorted vision that tends to worsen over the course of several hours or days. It is important to visit a doctor when unusual symptoms arise so the proper tests can be administered.
A physician can usually detect a vein occlusion by evaluating symptoms and performing a specialized x-ray procedure. A fluorescent dye is injected into a vein in the arm and allowed to enter circulation. X-rays are taken to trace the path of the dye to the site of a suspected occlusion. If the dye does not flow through the site quickly or reverses its course, a confident diagnosis can be made.
Anticoagulant medications such as warfarin and heparin may be given intravenously to help break apart blood clots in veins. If cholesterol buildup is responsible for symptoms, drugs to lower blood pressure and widen veins may be prescribed. Surgery may be needed in serious cases to remove or repair a vein. A stent may be permanently fixed into a blood vessel to help hold it open. Retinal occlusions are commonly treated with laser therapy to destroy damaged veins.