How do I know if I have cancer?

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How do I know if I have cancer?

Signs and symptoms are the manifestation of disease, in this case, cancer. They indicate that your body is trying to communicate that something is not right.

Cancer is made up of a group of diseases that can cause almost any sign or symptom. The signs and symptoms depend on where the cancer is, its size and how much it is affecting the organs or tissues. If the cancer has spread (metastasized), signs or symptoms may appear in different parts of the body.

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Cancer symptoms

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As the cancer cells expand, they can start to press on nearby organs, blood vessels and nerves. This pressure is what causes some signs and symptoms of cancer.

If cancer is found in critical area, like in certain parts of the brain, even the smallest tumor can cause symptoms.

The following infographic lists the general signs and symptoms of cancer. In any case, it is important to remember that just because you have any of these symptoms, does not mean that you necessarily have cancer; there are many other causes.

You should pay attention to see if these symptoms persist or get worse over time, in which case, you should consult your doctor to get a diagnosis.

Unexplained weight loss

Loss of 5 kilograms or more can be the first sign of cancer

Possible related cancer: pancreas, stomach, esophagus, or lung


High body temperature of 38° C (100.5 °F) or higher. More common when the immune system has been affected

Possible related cancer:  can be associated with any/all types of cancer


Extreme fatigue that doesn’t improve with rest

Possible related cancer: early stages of leukemia and some colon or stomach cancers, due to blood loss


The intensity of the pain can depend on the type, stage (extension) and the pain spectrum (pain tolerance). Initially, the pain is light, but keeps increasing

Possible related cancer: bone or testicular cancer

Changes in skin

  • Skin appears darker (hyperpigmentation)
  • Yellow eyes and skin (jaundice)
  • Reddened skin (erythema)Itching
  • Excessive hair growth

Possible related cancer: skin cancer

Changes to intestinal habits or bladder

  • Persistent diarrhea
  • Painful urination
  • Bloody urine
  • Frequent need to urinate (more than normal)

Possible related cancer: colon, bladder and prostate

Bruises that don’t heal

The blood flow is reduced in some parts of the skin, making them more susceptible to developing injuries that don’t heal

Possible related cancer: any part of the body

White spots in the mouth or on the tongue

These spots are called leukoplakia and can be precancerous areas caused by frequent irritation (smoking)

Possible related cancer: mouth or tongue cancer

Bleeding or abnormal secretion

  • Coughing blood
  • Bloody stools
  • Abnormal vaginal bleeding
  • Bloody urine
  • Bloody discharge from the nipple

Possible related cancer: can occur in early or advanced stages of lung, colon, rectum, cervical, bladder, kidney or breast cancer

Growth or lump in the breast

Can be an early or more advanced sign of cancer, but it is important to self-examine the breast, to detect this symptom. Some breast cancers also cause red or swollen skin.

Possible related cancer: breast cancer

Indigestion or difficulty swallowing

Feeling that food gets stuck in the throat or the chest.

Possible related cancer: stomach or throat cancer

Recent change in the appearance of a mole or freckle

Change in color, size, shape or border, or bleeding

Possible related cancer: skin cancer

Persistent cough or hoarseness

Persists for more than 3 weeks

Possible related cancer: larynx or thyroid glands


Other symptoms of cancer to look out for

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The aforementioned signs and symptoms are the most common in cancer, but there are also many others that we have not listed.

If you notice any significant change in how your body works or in the way you feel, especially if it lasts a long time or gets worse, tell your doctor. If it has nothing to do with cancer, your doctor can tell you more about what is happening and, if necessary, treat it. If the symptoms are cancer-related, telling your doctor will increase your chances of being diagnosed in the early stages.

Remember that this information could also help a loved one, so why not share it and help them get informed?