Signs and symptoms are ways the body lets you know that you have an injury, illness, or disease.
Signs and symptoms of cancer depend on where the cancer is, how big it is, and how much it affects nearby organs or tissues. If a cancer has spread (metastasized), signs or symptoms may appear in different parts of the body.
A cancer can grow into,or begin to push on nearby organs, blood vessels, and nerves. This pressure causes some of the signs and symptoms of cancer.
A cancer may also cause symptoms like fever, extreme tiredness (fatigue), or weight loss. This may be because cancer cells use up much of the body’s energy supply. Or the cancer could release substances that change the way the body makes energy. Cancer can also cause the immune system to react in ways that produce these signs and symptoms.
Most signs and symptoms are not caused by cancer but can be caused by other things. If you have any signs and symptoms that don't go away or get worse, you should see a doctor to find out what’s causing them. If cancer is not the cause, a doctor can help figure out what the cause is and treat it, if needed.
For instance, lymph nodes are part of the body’s immune system and help capture harmful substances in the body. Normal lymph nodes are tiny and can be hard to find. But when there’s infection, inflammation, or cancer, the nodes can get larger. Those near the body’s surface can get big enough to feel with your fingers, and some can even be seen as swelling or a lump under the skin. One reason lymph nodes may swell is if cancer gets trapped there. So, if you have unusual swelling or a lump, you should see your doctor to figure out what’s going on.
Here are some of the more common signs and symptoms that may be caused by cancer. However, any of these can be caused by other problems as well.
The signs and symptoms listed above are the more common ones seen with cancer, but there are many others that are not listed here. If you notice any major changes in the way your body works or the way you feel – especially if it lasts for a long time or gets worse – let a doctor know. If it has nothing to do with cancer, the doctor can find out more about what’s going on and, if needed, treat it. If it is cancer, you’ll give yourself the chance to have it treated early, when treatment is more successful.
Sometimes, it’s possible to find cancer before you have symptoms. The American Cancer Society and other health groups recommend cancer-related check-ups and certain tests for people even though they have no symptoms. This helps find certain cancers early. You can find more information on early detection at the American Cancer Society Guidelines for the Early Detection of Cancer.
And keep in mind, even if you have cancer-related screening tests, it’s still important to see a doctor if you have any new or worsening signs or symptoms. The signs and symptoms might mean cancer or another illness that needs to be treated.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
National Cancer Institute. Symptoms of Cancer. Cancer.gov. https://www.cancer.gov/about-cancer/diagnosis-staging/symptoms. Updated May 16, 2019. Accessed November 6, 2020.
Last Revised: November 6, 2020
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