Cancer is a problem that will affect nearly 40 percent of women and half of men in their lifetimes. Most people know at least one person who has been affected by cancer. There is nothing that you can do that will 100 percent stop cancer from developing. However, if you understand the risk factors, then you will have a better idea of what strides you can make as far as cancer prevention.

Here are the most common risk factors for all types of cancer:

1. Family history

It is important to know your family health history. If certain forms of cancer run in your family (i.e., breast cancer or prostate cancer), then you will automatically be at a higher risk for it. It is estimated that 5 to 20 percent of cancers are linked to genetics. You can also get genetic testing done to assess your overall risk of certain cancers.

2. Using tobacco

Tobacco has been linked to many forms of cancer, including lung, mouth, tongue, and esophageal cancer. It is estimated that 90 percent of lung cancers are caused by tobacco use. One of the easiest ways to reduce your overall risk of cancer is to avoid tobacco. If you already use it, then quit.

3. Viral infections

HPV, short for the human papillomavirus, is a type of viral infection that has been linked to oral cancer, cervical cancer and penile cancer. There are HPV vaccinations that can prevent certain strains of the virus. Ask your doctor if you are a candidate for the HPV vaccination.

4. Obesity

Obesity plays a role in about 40 percent of cancers. Colon cancer, breast cancer, thyroid cancer and pancreatic cancer have been linked to excess body weight. There are several ways that excess body weight can put you at risk for cancer. If you are overweight, then you have higher levels of inflammation in your body and inflammation can lead to cancer development. Excess body weight can also cause hormonal changes that can lead to cancer.

5. Alcohol usage

Excess alcohol use has been linked to throat cancer, breast cancer and liver cancer. Any type of alcoholic beverage that you consume can put you at risk for cancer. When an alcoholic beverage breaks down, it produces something called acetaldehyde. This can cause damage to your DNA, which can cause cancerous cells to develop.

6. Chemical exposure

Americans are exposed to 100,000 chemicals each year. You can find them in your personal products, lawn care products, household products and foods. Vinyl, chloroform, benzene and arsenic are examples of some of the carcinogens that can ruin your health and raise your cancer risk. That is why it is a good idea for you to read the labels on everything that you buy.

7. Radiation and UV exposure

We are exposed to radiation in a variety of ways. The ultraviolet rays from the sun have radiation. You can limit your exposure to ultraviolet rays by wearing sunscreens. Other sources of radiation include x-rays, nuclear medicine procedures, building materials, fluorescent lamps, coal and gas. There are a few things that you can do to protect yourself from radiation. For example, if you work around radiation, then you can wear shields. Medical professionals make sure that you are properly protected if you are getting an x-ray or a procedure that requires radiation. Additionally, you can use a radon reduction system if you live near a place that has high radon levels.