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Signs You Have Cancer and Don't Know It

Don’t ignore these common symptoms of cancer.
FACT CHECKED BY Emilia Paluszek

Cancer can be notoriously difficult to test for early in a cost-effective and accurate way. "It's a scary question," says Dr. Francis Barany, Microbiology and Immunology, Weill Cornell Medicine. "Do I have a hidden cancer within me? Think of cancer as a garbage truck. As the truck moves up the small side streets, occasionally it drops a piece of garbage behind it. A couple walking in the same neighborhood may see a plastic bottle on one street and a newspaper on another but not know where they came from. It's only if they keep seeing more garbage that they may come to the conclusion that a garbage truck is making its rounds… We don't know ahead of time what the garbage truck is actually going to drop, and each cancer drops different garbage into the bloodstream. Not only that, but each individual's garbage looks different. So this is really tricky." Here are five signs of hidden cancer, according to doctors. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.



Woman suffering from cold, virus lying on the sofa under the blanket

Ongoing fatigue that doesn't get better no matter how much you rest could be a sign of cancer, experts say. "Extreme fatigue that doesn't get better with rest can be an early sign of cancer," says Johns Hopkins Medicine. "Cancer uses your body's nutrients to grow and advance, so those nutrients are no longer replenishing your body. This 'nutrient theft' can make you feel extremely tired."


Excessive Bloating

Young woman suffers, writhes in abdominal pain lying on couch in living room at home interior

Unexplained bloating could be a sign of stomach cancer, doctors warn. "Stomach cancer can make the wall of your stomach very rigid and reduce its capacity to store food," says general surgeon Daniel Joyce, MBBCh. "In cases where the stomach cancer spreads to the lining of the abdomen, it can cause an accumulation of fluid within your abdominal cavity."


Difficulty Swallowing

Woman touches her throat.

Constant issues with swallowing food could be a sign of cancer. "Does food get stuck in your throat? Do you have difficulty swallowing? This is called dysphagia. It may or may not be a sign of cancer. If it gets worse over time, you should call your doctor," advises Johns Hopkins Medicine


Unexplained Swelling and/or Lumps

dermatologist examining mole on back of male patient in clinic

Unexplained lumps should never be ignored, experts advise. "Tell your doctor about new lumps or other symptoms that cannot be explained or that don't go away in a few weeks," says oncologist Dale Shepard, MD, PhD.


Weight Loss Or Weight Gain

weight gain

Unexplained weight changes can be a sign of serious illness. "For many people with cancer, this unexplained weight loss is one of the first indications of the disease," says hematologist and oncologist Munveer Bhangoo, MD. "Someone who loses this amount of weight without a clear reason should see their physician to determine what is causing it."

Ferozan Mast
Ferozan Mast is a science, health and wellness writer with a passion for making science and research-backed information accessible to a general audience. Read more about Ferozan
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