Cancer, or known in medicine as malignant neoplasm is a disease whose cells show rapid and uncontrollable growth by dividing themselves beyond the limits of what is normal. These cells attack and bond with the neighboring tissues, and sometimes they cause metastasis, where they spread onto other parts in the body through the lymph nodes and the blood stream. These features separate cancer from the benign tumors that are limited in growth and don’t cause metastasis.
We can roughly divide the cancer symptoms into three groups:
Local symptoms – unusual swellings and lumps (tumors), bleeding, and pain and/or ulceration. Pressure in the surrounding tissues can cause symptoms like the ones of hepatitis A (yellow eyes and skin).
Metastasis symptoms – enlarged lymph nodes, sough and hepatomegaly (abnormal enlargement of the liver), bone pain, fragility of the affected bones, and neurological symptoms. Even though when cancer is in advanced stage can cause pain, that’s not the first symptom.
Systematic symptoms – sudden weight loss, loss of appetite, exhaustion, cachexia, abnormal sweating, anemia, and specific paraneoplastic phenomena (specific conditions caused by cancer like thrombosis or hormonal changes).
Cancer can cause these conditions, but it doesn’t necessarily mean that they indicate cancer.
Scientists try to learn how cancer spreads though the body, and this video shows clearly how it is happening: