Cancer and its treatments can cause changes in the body
Some cancers may block channels in the body and stop particular body systems working so well. Some cancers may cause changes in the body by pressing on surrounding body tissues or organs.
The blood and circulatory system and how cancer affects it
Some cancers and cancer treatments can change the number of blood cells circulating in the blood. Cancers can spread by shedding cells into the bloodstream that may then settle in another part of the body.
The lymphatic system normally helps to trap and destroy cancer cells as well as bacteria and other harmful organisms.Sometimes cancer cells get trapped in lymph nodes close to the cancer and may then start to grow there.
The hormone system is a network of glands and organs in the body that produce hormones. Cancer and its treatments can sometimes change hormone levels and cause side effects. But some treatments can help to control cancer or prevent it coming back by changing particular hormone levels.