Symptoms of Cancer
Cancer manifests itself in a very variable. It usually develops over many years before symptoms appear. The following 
symptoms may be signs of cancer. In their presence, consult a doctor.
* A palpable mass, especially if it increases the volume of a nodule in one breast under the skin, a lymph node, etc..
* A mole or skin spot that changes in appearance, color or size, or bleeding.
* A bleeding: blood in the sputum, urine or stool. For women, vaginal blood loss during the cycle or after menopause.
* Symptoms: Persistent cough and unexplained hoarseness for more than four weeks, difficulty swallowing, nausea and vomiting, a sore that does not heal in three weeks, diarrhea or constipation for six weeks or more.
* A withdrawal or discharge from the nipple.
* Headaches and recurrent violence.
* Extreme fatigue.
* A rapid weight loss, unexplained.
People at risk
* Some families are more frequently affected by cancer. There would, in these families, genetic predisposition to cancer, passed from one generation to another. This may be the case for breast, ovarian and colon cancer. Even in people whose genetic background predisposes to cancer, the risk of being a fair and depends largely on the lifestyle and environment.
* People who have had cancer.
* Persons aged 50 and older. As we age, the risk of cancer is increasing, because the defense mechanisms are less effective and the duration of exposure to risk factors increases.
Risk Factors
Scientific research has revealed risk factors for most cancers. Some of these factors increase the risk of developing a particular type of cancer, while others have a more tenuous.
The two main risk factors
* Smoking. The carcinogens in cigarette smoke does not only attack the lungs, they are also involved in the risk of cancers of the mouth, larynx, cervix, breast, stomach, bladder and many others. Smoking is responsible for 30% of deaths due to cancer. Show details Lung Cancer.
* Poor nutrition. The Western diet contains too many calories, too much animal protein, too much fat, too much salt and too much sugar, and low fruit and vegetables as well as whole grains. According to the World Health Organization, dietary factors are responsible for 30% of cancers in the West, and about 20% in countries développement5.
Other important risk factors
* Obesity and overweight. Consequence of physical inactivity and poor diet, excess weight would be a major risk factor for several cancers, including esophagus, colon, breast, endometrial and rein5. See our Obesity sheet.
* Physical inactivity. In addition to causing overweight, physical inactivity would prevent the proper operation of certain mechanisms needed to maintain health. Physical fitness reduces the risk of colon cancer and cancer sein5.
* Exposure to carcinogenic chemicals. It would cause 4% of all cancers in industrialized countries. These include, chemicals that can be exhibited in a work environment (arsenic, asbestos, benzene, etc..), Some cleaning products, solvents and paint, radon Earth that seeps into the basement of houses and pesticides on land (a recognized cause of leukemia in children).
* Exposure to radioactive substances.
* A chronic infection. Some microbes, especially viruses, can cause cancer. They were responsible for 18% of all cases of cancer in the world, especially in developing countries (about 5% in industrialized countries). For example, include human papillomavirus (cancer of the cervix), hepatitis B and C (liver cancer), the liver fluke (bile duct cancer), Helicobacter pylori ( stomach cancer) and human immunodeficiency virus (HIV) (Kaposi sarcoma and lymphoma).
* The consumption of alcohol. Research has shown a link between alcohol consumption (even when it is moderate) and several types of cancer: breast, colon and rectum, esophagus, larynx, liver, mouth and pharynx68, 69. The more alcohol consumed, the greater the risk of cancer rises, regardless of the type of alcohol (wine, beer or spirits).
* The excessive exposure to sunlight. Ultraviolet (UV), high dose, can cause skin cancer in the long term.