The symptoms of Kaposi's sarcoma (KS) vary according to where the lesions or growths develop.

The skin

Any part of the skin, including the inside of the mouth, can be affected by KS. KS usually appears as small, painless flat areas (lesions) or lumps. They can be different colours including brown, red, blue and purple. They often look like bruises but do not lose their colour when pressed like a bruise does.

Although KS growths may start in one place, they can develop in more than one area. The growths often eventually merge into each other to form a larger tumour, giving a patchwork appearance.

The internal organs

The internal organs most commonly affected by KS are the lymph nodes, lungs and organs of the digestive system. The symptoms of KS depend on which organs are affected.

When the lymph nodes are affected, there may be swelling in the arms and legs, which can be very painful and uncomfortable. This is known as lymphoedema and is caused by the KS cells blocking the flow of fluid through the lymph nodes. As a result, the tissue fluid backs up, causing swelling in the body's tissues.

When the lungs are affected, symptoms may include breathlessness. When the organs in the digestive system are affected, symptoms include nausea, vomiting and bleeding.