Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems.
The three ways that cancer spreads in the body are through:
- Tissue: cancer invades the surrounding normal tissue
- Lymph system: cancer invades the lymph system and travels through the lymph vessels to other places in the body
- Blood: cancer invades the veins and capillaries and travels through the blood to other places in the body
Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for the organ or type of cell in which they start -- for example, cancer that begins in the colon is called colon cancer; cancer that begins in basal cells of the skin is called basal cell carcinoma.
Many of the most common types of cancer are found here. For others, visit the National Cancer Institute website, the source of disease information on this website.
Your blood is living tissue made up of liquid and solids. The liquid part, called plasma, is made of water, salts and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells and platelets.
Red blood cells deliver oxygen from your lungs to your tissues and organs. White blood cells fight infection and are part of your body's defense system. Platelets help blood to clot. Bone marrow, the spongy material inside your bones, makes new blood cells. Blood cells constantly die and your body makes new ones. Red blood cells live about 120 days, platelets six days and white cells less than one day.
There are many types of blood disorders, including: bleeding disorders, platelet disorders, bone marrow disorders, hemophilia and anemia. There are also several cancers of the blood including Hodgkin and non-Hodgkin lymphoma, leukemia and myeloma.