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Could This Be Cancer?

worried senior woman rubs her forehead

Most of the possible signs and symptoms of cancer that we notice turn out to be something that isn’t serious. For example, a new mole or lump or a headache that won’t go away is not likely to be cancer, but should be checked out by a doctor just to be sure. That gives you the best chance of getting the problem treated, whether it’s cancer or something else. For many health conditions, treatment works better the earlier it’s started.

It would be helpful if our bodies gave us a clear message when we had cancer, but cancer is complicated. It’s a group of diseases that can cause almost any sign or symptom, depending on where it starts or even where it has spread. What makes it even more complicated is that many other health problems that aren’t cancer can cause the same signs and symptoms as cancer does.

Possible signs and symptoms of cancer

If you notice any of these signs and symptoms, get them checked out – especially if they last for a long time or get worse. Usually whatever is causing the problem isn't cancer, but seeing a doctor is the only way to find out.

  • Unexplained weight loss: Losing 10 pounds or more without knowing the reason
  • Fatigue: Extreme tiredness that doesn’t get better with rest
  • Pain: Especially back or belly pain, or a headache that doesn’t go away or get better with treatment
  • Skin changes: Any wart, mole, or freckle that changes color, size, or shape, or that loses its sharp border should be seen by a doctor right away. Tell your doctor about other skin changes too, including: darkening, yellowing, reddishness, itching, and excessive hair growth.
  • Sores that do not heal: These can be on the skin, in the mouth, or on the genitals.
  • Change in bowel habits or bladder function: Long-term constipation, diarrhea, a change in the size of the stool, pain when passing urine, blood in the urine, or a change in bladder function (such as needing to go more or less often than usual)
  • White patches inside the mouth or white spots on the tongue: Certain infections, smoking, or other tobacco use can cause pre-cancerous areas. If not treated, these patches or spots might become cancer.
  • Unusual bleeding or discharge: This can include coughing up blood, blood in the stool (which can look like very dark or black stool), abnormal vaginal bleeding, blood in the urine, or a bloody discharge from the nipple.
  • Lump: This can be anywhere, but mostly occurs in the breast, testicle, lymph nodes (glands), and the soft tissues of the body. Some breast cancers show up as red or thickened skin rather than a lump.
  • Indigestion or trouble swallowing that doesn’t go away 
  • Nagging cough or hoarseness that doesn’t go away

These signs and symptoms are more common, but they aren’t the only indications of cancer. 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.

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 editors and translators with extensive experience in medical writing.


Could This Be Skin Cancer?

Find out what skin cancer looks like through the examples in our skin cancer gallery, and learn how to check your skin for warning signs.