What Causes Cancer?
Cancer starts when cells start to grow and divide too much or don’t die when they should. These abnormal cells form tumors (or masses) that can spread to other parts of the body. Cells can also change in other ways that cause the body’s systems to stop working normally, such as when they block blood vessels or make enzymes that break down normal tissue and waste.
There are more than 100 types of cancer, but they all have one thing in common: They start when normal cells grow out of control. Then they build up, crowding out other cells and blocking the flow of oxygen or nutrients to those cells.
Normal cells need a steady supply of oxygen and nutrients to grow, survive and perform their jobs. They get those nutrients from the blood. The body’s immune system usually kills any cancer cells that aren’t needed or can’t be controlled. But sometimes, the cancer cells escape and grow uncontrollably.
Cancer can start in any part of the body. It can develop in bones, soft tissues, the blood or organs such as the liver, lungs or brain. Cancer cells can also spread to other parts of the body through the blood or lymphatic system. The new cancer cells may begin to grow in a nearby area or they may spread to areas far away from where the original cancer started, which is called metastasis.
Scientists know what causes most kinds of cancer, but they are still learning more about how and why cancers start. They have found that some cancers are more likely to occur if certain genes become damaged or out of balance. These genetic changes are called mutations or alterations. The three main types of gene alterations that contribute to cancer are proto-oncogenes, tumor suppressor genes and DNA repair genes.
People can take steps to prevent some kinds of cancer by eating a healthy diet, exercising regularly and avoiding tobacco and excessive sun exposure. They can also limit their use of chemicals at home and at work, including weed killers, plastics and some household products. These chemicals are known as carcinogens, and they can damage the DNA in cells, raising your risk for cancer.
Some cancers start in the skin, so it’s important to protect yourself from sunburn and cover up with clothing and sunscreen when you go outside. It’s also important to use a sunscreen that has an SPF of at least 30 or higher. Some research suggests that taking lots of antibiotics when you’re young can raise your risk for certain cancers, so it’s a good idea to talk to your doctor before starting antibiotics. It’s also a good idea to report any unusual symptoms right away, even if they don’t seem serious. The sooner cancer is diagnosed, the easier it is to treat.
Cancer starts when cells start to grow and divide too much or don’t die when they should. These abnormal cells form tumors (or masses) that can spread to other parts of the body. Cells can also change in other ways that cause the body’s systems to stop working normally, such as when they block blood vessels or make enzymes that break down normal tissue and waste. There are more than 100 types of cancer, but they all have one thing in common: They start when normal cells grow out of control. Then they build up, crowding out other cells and blocking the flow of oxygen or nutrients to those cells. Normal cells need a steady supply of oxygen and nutrients to grow, survive and perform their jobs. They get those nutrients from the blood. The body’s immune system usually kills any cancer cells that aren’t needed or can’t be controlled. But sometimes, the cancer cells escape and grow uncontrollably. Cancer can start in any part of the body. It can develop in bones, soft tissues, the blood or organs such as the liver, lungs or brain. Cancer cells can also spread to other parts of the body through the blood or lymphatic system. The new cancer cells may begin to grow in a nearby area or they may spread to areas far away from where the original cancer started, which is called metastasis. Scientists know what causes most kinds of cancer, but they are still learning more about how and why cancers start. They have found that some cancers are more likely to occur if certain genes become damaged or out of balance. These genetic changes are called mutations or alterations. The three main types of gene alterations that contribute to cancer are proto-oncogenes, tumor suppressor genes and DNA repair genes. People can take steps to prevent some kinds of cancer by eating a healthy diet, exercising regularly and avoiding tobacco and excessive sun exposure. They can also limit their use of chemicals at home and at work, including weed killers, plastics and some household products. These chemicals are known as carcinogens, and they can damage the DNA in cells, raising your risk for cancer. Some cancers start in the skin, so it’s important to protect yourself from sunburn and cover up with clothing and sunscreen when you go outside. It’s also important to use a sunscreen that has an SPF of at least 30 or higher. Some research suggests that taking lots of antibiotics when you’re young can raise your risk for certain cancers, so it’s a good idea to talk to your doctor before starting antibiotics. It’s also a good idea to report any unusual symptoms right away, even if they don’t seem serious. The sooner cancer is diagnosed, the easier it is to treat.