DISEASES EVERYONE SHOULD KNOW ABOUT
The main cause of cancer is mutations, or changes to the DNA in your cells. Genetic mutations can be inherited. They can also occur after birth as a result of environmental forces.
These external causes, called carcinogens, can include:
physical carcinogens like radiation and ultraviolet (UV) light
chemical carcinogens like cigarette smoke, asbestos, alcohol, air pollution, and contaminated food and drinking water
biological carcinogens like viruses, bacteria, and parasites
According to the WHOTrusted Source, about 33 percent of cancer deaths may be caused by tobacco, alcohol, high body mass index (BMI), low fruit and vegetable consumption, and not getting enough physical activity.
Risk factors
Certain risk factors may increase your chance of developing cancer. These risk factors can include:
tobacco use
high alcohol consumption
an unhealthy diet, characterized by red and processed meat, sugary drinks and salty snacks, starchy foods, and refined carbohydrates including sugars and processed grains, according to a 2017 review
a lack of physical activity
exposure to air pollution
exposure to radiation
unprotected exposure to UV light, such as sunlight
infection by certain viruses including H. pylori, human papillomavirus (HPV), hepatitis B, hepatitis C, HIV, and the Epstein-Barr virus, which causes infectious mononucleosis
The risk of developing cancer also increases with age. In general, the risk of developing cancer appears to increase until the age of 70 to 80Trusted Source and then diminish, according to the National Cancer Institute (NCI).
A 2020 reviewTrusted Source suggests this may be the result of:
less effective cell repair mechanisms that come with aging
buildup of risk factors over the course of life
duration of exposures to carcinogens
Some existing health conditions that cause inflammation may also increase your risk of cancer. An example is ulcerative colitis, a chronic inflammatory bowel disease.