Updated 13 April 2017

7 dangers signs of cancer

There is no single tell-tale sign that you have cancer. Look-out for the following common signs and symptoms related to cancer.

We all fear cancer, but different cancers present in different ways, and there is no single tell-tale sign that you definitely have cancer.

The following is a list of some of the most common signs and symptoms of cancer. Having any one or all of the following does not mean you have cancer, but you must go and see your doctor to get them checked out.

1. Unexplained, significant weight loss

One of the most common presenting complaints in people with cancer is unexplained weight loss. Some people report suddenly dropping two to three clothes sizes.

2. Excessive tiredness

This can be due to higher metabolic demands on the body because of the high energy requirements of cancerous cells. Tiredness that does not get better with rest is a reason for concern. Some cancers may cause blood loss (like gastrointestinal tract cancers) which can also cause tiredness

3. Persistent sores that do not heal

Persistent sores that do not heal despite ointments and treatments should be examined by your doctor.  A change in the colour, size and contours of moles is also reason for concern.

Cancers that commonly present this way are cancer of the oral cavity, skin cancers and cancers of the penis and vagina

4. Change in bowel and bladder habits

Persistent constipation, diarrhoea, occasional pain passing stool and a change in the size of your stools are all reasons for concern. If you are having difficulty passing urine or notice blood in your urine, you should have it checked out.

Cancers that commonly present this way are colon cancer, rectal cancer, bladder cancer.

5. Odd bleeding or discharges

Bleeding from any body cavity is reason for concern. If you notice blood in your stool, your urine or from your mouth, your doctor should know about it. Bloody streaks in your phlegm are also reason for concern. Foul smelling discharge or blood from your vagina should be looked at by your doctor. In most cases this merely indicates an infection, but have it checked out anyway. 

Cancers that commonly present this way are coughing up blood - lung cancers, bleeding or discharge from the vagina - uterine cancer or cervix cancer

6. Hoarseness or change in your voice

Persistent hoarseness may indicate cancer of the larynx or any structure of the neck.  If you or your family notice a change in your voice that does not go away, you should visit your doctor for further investigation.

Cancers that commonly present this way: laryngeal cancer, thyroid cancer, lung cancer

7. Lumps or bumps

Any lump or bump that enlarges, hardens or changes the skin above should be examined for possible malignancy. Breasts and testicles should regularly be palpated to check for any changes in contour, size, and hardness. It is important to remember that cancerous growths are in most cases painless.  

Cancers that commonly present this way: breast cancer, testicular cancer

Other signs and symptoms to be on the lookout for:

Low-grade fevers, chronic headaches, bone pain and persistent nausea and vomiting should also be checked out by your doctor.

Read More:

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Many smokers fail to quit after cancer diagnosis


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