How does cancer make people sick?

Cancer can make people sick in a number of ways, including:

* By taking over the body's normal tissues and organs: As cancer cells grow and multiply, they can crowd out healthy cells and disrupt the function of organs and tissues. This can lead to a variety of symptoms, depending on the location of the cancer. For example, lung cancer can cause difficulty breathing, breast cancer can cause breast pain and swelling, and colon cancer can cause abdominal pain and diarrhoea.

* By damaging the immune system: Cancer can also damage the immune system, making people more susceptible to infections and other health problems. This is because cancer cells can produce substances that suppress the immune system, and they can also damage bone marrow, where immune cells are made.

* By producing hormones and other substances that can affect the body: Some cancer cells can produce hormones and other substances that can affect the body in a variety of ways. For example, breast cancer cells can produce estrogen, which can stimulate the growth of cancer cells. Lung cancer cells can produce a substance called vascular endothelial growth factor (VEGF), which can cause new blood vessels to grow, which can supply the cancer with nutrients.

* By causing metabolic changes in the body: Cancer can also cause metabolic changes in the body, leading to a variety of symptoms. For example, cancer can cause weight loss, fatigue, and fever. Cancer can also lead to the development of anemia, which is a condition in which the body does not have enough red blood cells.

The symptoms of cancer can vary depending on the type of cancer and the stage of the cancer. Some cancers may not cause any symptoms in the early stages, while others may cause symptoms that are severe and debilitating. If you are experiencing any symptoms that are new or unusual, it is important to see your doctor to rule out cancer.