How do we classify cancer?
Doctors classify cancer using the site at which the cancer started or the type of tissue where the cancer originated. For example, a person can have breast cancer, which is usually a type of carcinoma, or cancer that arises from epithelial tissue.
What are external causes of cancer?
Environmental factors that cause cancer
- Lifestyle factors (nutrition, tobacco use, physical activity)
- Natural occurring exposures (ultraviolet light, radon gas, infectious agents)
- Medical treatments (radiation and medicine)
- Workplace and household exposures.
What is an internal cause of cancer?
Some factors that cause cancer are related to systems inside the body. For example, abnormal hormone levels in the bloodstream can cause cancer. A weakened immune system can also lead to cancer. Hereditary factors can also increase the risk of developing cancer.
What are the internal and external risk factors for cancer?
The most common risk factors for cancer include aging, tobacco, sun exposure, radiation exposure, chemicals, and other substances, some viruses and bacteria, certain hormones, family history of cancer, alcohol, poor diet, lack of physical activity, or being overweight.
What are the 7 warning signs of cancer?
These are potential cancer symptoms:
- Change in bowel or bladder habits.
- A sore that does not heal.
- Unusual bleeding or discharge.
- Thickening or lump in the breast or elsewhere.
- Indigestion or difficulty in swallowing.
- Obvious change in a wart or mole.
- Nagging cough or hoarseness.
Why is cancer so common now?
The main reason cancer risk overall is rising is because of our increasing lifespan. And the researchers behind these new statistics reckon that about two-thirds of the increase is due to the fact we’re living longer. The rest, they think, is caused by changes in cancer rates across different age groups.
How do cancers spread?
When cancer spreads, it’s called metastasis. In metastasis, cancer cells break away from where they first formed, travel through the blood or lymph system, and form new tumors in other parts of the body. Cancer can spread to almost anywhere in the body. But it commonly moves into your bones, liver, or lungs.
What is the root cause of cancer?
Cancer is caused by changes (mutations) to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide.
What are the top 10 causes of cancer?
The germline mutations are carried through generations and increase the risk of cancer.
- Cancer syndromes.
- Bacteria and parasites.