Vascular system is made up of a network of blood vessels, which includes veins, arteries and capillaries. The inflammation of these blood vessels can occur in any part of the body and is referred to as Vasculitis. Vasculitis causes changes in the walls of blood vessels, such as thickening, weakening, narrowing and scarring. In certain cases the blood cells itself can invade the vessel wall, leading to damage of the surrounding tissue and obstruction of the vessel itself. Due to obstruction of vessel, the blood flow to a particular organ is reduced which damages the organ in the long run. The severity of this condition and its consequences depends on the site, size and extent of vessel involvement

The cause for many types of vasculitis is not known. In some cases, the immune system recognizes the body’s own blood vessels as foreign particle and starts acting against it, leading to swelling or leak of blood from the vessel. An allergic reaction to a medication, such as an antibiotic or diuretic, may also cause vasculitis. Hepatitis C and Hepatitis B infection can cause Cryoglobulinaemia and Polyarteritis nodosa respectively. Vasculitis can also occur as a result of certain immune disorders like rheumatoid arthritis, lupus and Sjogren's syndrome