Because there are two categories of major blood vessels -arteries and veins- there also are two major categories of vascular disease.

Artery diseases

• Arteriosclerosis: Arteries, which carry oxygen-rich blood throughout the body, can be narrowed by deposits called plaque laid down inside the artery wall.
• Peripheral arterial disease: Peripheral arterial disease (PAD) is a narrowing or blockage of the arteries in the arms or legs. In the legs, it can cause pain when walking (claudication). As the disease worsens, symptoms may occur during rest. Untreated, it can ultimately lead to gangrene and the loss of a limb. PAD cannot be cured, but it can be controlled by reducing risk factors such as high blood pressure or excess weight, stopping smoking; by developing a safe exercise program, and, when necessary, minimally invasive treatment or surgery.
• Aneurysms: Aneurysms occur when atherosclerosis weakens the arterial wall which then bulges out and can potentially rupture. Abdominal aortic aneurysm, a ballooning of the body's major artery, can be life-threatening.

Vein diseases

• Varicose veins: Veins return blood to the lungs and then to the heart for re-circulation. To move blood along, veins have gravity-fighting valves to keep blood from backing up and pooling, particularly in the legs. When these valves fail to work properly, bulging, painful veins, called varicose veins, can develop.
• Phlebitis: Phlebitis is the inflammation of a vein, which leads to swelling and pain.
• Deep vein thrombosis: A blood clot in one of the major veins, often in the legs. It poses a risk because the clot may break loose and travel to the lungs. A blood clot in the lung, called a pulmonary embolism, is very serious and potentially fatal.