Kaposi's sarcoma on the skin appears as a small, painless, flat area (lesion) or lump, ranging in colour from brown or brown-red to reddish purple. The lesions or lumps can develop quickly. Although there may be a single area at first, it is not uncommon for more than one to appear. Any part of the skin, including the inside of the mouth, can be affected. Often the lumps merge to form a larger tumour.

KS can also affect other parts of the body, most commonly the lymph nodes, the lungs and the organs of the digestive system. The signs and symptoms of internal KS depend on the area of the body that is affected. If the lymph nodes are affected, which is common in Aids-related KS, there may be swelling in the limbs. This is known as lymphoedema and is caused by the KS cells blocking the lymph nodes and disrupting the normal circulation of lymph fluid around the body. Lymphoedema can be a distressing and uncomfortable symptom, and while there is no actual 'cure' there are ways to relieve it.

Our section on lymphoedema gives useful advice about reducing lymphoedema through methods such as exercise and massage.

KS in the lungs commonly causes breathlessness, while a tumour in the digestive system (gut) may cause nausea, vomiting, and bleeding.