The word cancer is used to describe many different diseases, but they all start the same way – when one of our cells starts growing and multiplying out of control. The resulting growths are called tumours, and they can grow and spread anywhere in the body. These tumours can block the flow of blood, which means that your organs don’t get the oxygen and nutrients they need to work properly. They can also interfere with the function of your nerves, lungs, heart and digestive system. Cancer is a serious disease that can be very difficult to treat. Fortunately, there are a lot of things that can help prevent it, including a healthy lifestyle and regular check-ups.
Scientists have been studying cancer for a long time, but they’ve only recently learned how it develops. They knew that the genes that manage cell activity can change, but they didn’t know what happened to cause this. Cancer is now believed to happen when the genes that control how fast cells grow and divide mutate. These mutations can lead to cells that don’t die when they should or that continue to divide even when there are no new growths. Over time, these abnormal cells can build up to form a tumour.
In order for a cell to become cancerous, it needs to have the right genes and the right environment. The genetic changes that cause cancer can be caused by a variety of factors, including sunlight, tobacco, certain viruses, some medications and many other environmental chemicals, such as carcinogenic metals and radiation. Some of these chemicals can be found naturally in the environment, while others are introduced through human activities or by living or working in certain places.
Cancer can also start when certain types of cells become damaged by radiation or chemotherapy drugs. The damage to these cells causes them to change, and the changes can be passed on from generation to generation. Scientists are still learning about how cancer causes and how to prevent it, but there is no single factor that can be blamed for most cases of cancer.
The most common type of cancer is breast cancer, which can be caused by a number of things, including hormones, alcohol and some viruses. It can also be triggered by having children late in life or by certain genetic disorders. Other cancers can be caused by infections, such as hepatitis B and C or Epstein-Barr virus. People who live in countries with high rates of cancer can also be at risk for developing certain types of cancer, as well as those who have been exposed to industrial pollutants, certain types of radiation or radiotherapy and certain occupational hazards such as asbestos.