As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are flexible, hollow tubes that carry blood to every part of the body.
- Arteries carry oxygen-rich blood away from the heart.
- Veins return oxygen-poor blood back to the heart.
Veins are flexible, hollow tubes with flaps inside called valves. When your muscles contract, the valves open and allow blood to move through the veins. When your muscles relax, the valves close, keeping blood flowing in one direction through the veins. Veins become larger and larger as they get closer to the heart. The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the abdomen and legs into the heart.
If the valves inside your veins become damaged as a result of venous disease, the valves may not close completely, allowing blood to leak backward or flow in both directions.
What are venous diseases?
Venous diseases include:
Which can be found in the legs, arms, veins of the internal organs (kidney, spleen, intestines, liver, pelvic organs), in the brain (cerebral vein thrombosis), in the kidneys (renal vein thrombosis), or in the lungs (pulmonary embolism). Get more information about blood clotting disorders.
Deep vein thrombosis
Deep vein thrombosis (DVT) is a blood clot occurring in a deep vein (including upper extremity — arms — and lower extremity — legs. Even though deep vein thrombosis itself is not life-threatening, the blood clot has the potential to break free and travel through the bloodstream, where it can become lodged in the blood vessels of the lung (known as a pulmonary embolism). This can be a life-threatening condition.
Superficial venous thrombosis or phlebitis
Superficial venous thrombosis or phlebitis is a blood clot that develops in a vein close to the surface of the skin. These types of blood clots do not usually travel to the lungs unless they move from the superficial system into the deep venous system first. Typically, however, they cause pain.
Chronic venous insufficiency
Chronic venous insufficiency is characterized by pooling of blood, chronic leg swelling, increased pressure, increased pigmentation or discoloration of the skin, and leg ulcers known as venous stasis ulcer.
Varicose and spider veins
Varicose and spider veins are abnormal, dilated blood vessels caused by a weakening in the blood vessel wall.
Ulcers are caused by static blood flow or venous stasis ulcers. Ulcers are wounds or open sores that will not heal or keep returning. Venous stasis ulcers are located below the knee and are primarily found on the inner part of the leg, just above the ankle.