What Is Cancer?
Cancer is the general term for a group of more than 100 diseases in which cells in a part of the body begin to grow out of control. Although there are many kinds of cancer, they all start because abnormal cell growth.Cancer also has the ability to spread throughout your body. Untreated cancers can cause serious illness and even death. In 2007, cancer caused about 13% of all human deaths worldwide (7.9 million). Rates are rising as more people live to an old age and as mass lifestyle changes occur in the developing world.
Cancer cells often travel to other parts of the body, where they begin to grow and form new cáncer (tumors) that replace normal tissue. This process is called metastasis. It happens when the cancer cells get into the bloodstream or lymph vessels of our body.
A symptom is also a signal of disease, illness, injury, or that something is not right in the body. Symptoms are felt or noticed by the person who has them, but may not be easily seen by anyone else. For example, weakness, aches, and feeling short of breath may be symptoms of pneumonia.
A sign is a signal that something is not right in the body. But signs are signals that can be seen by someone else - maybe a loved one, or a doctor, nurse, or other health care professional. Fever, fast breathing, and abnormal lung sounds heard through a stethoscope may be signs of pneumonia.
Having one sign or symptom may not be enough to figure out what's causing it. Sometimes, a patient's signs and symptoms still don't give the doctor enough clues to figure out the cause of an illness. Then medical tests, such as x-rays, blood tests, or a biopsy may be needed.
You should know some of the general signs and symptoms of cancer. But remember, having any of these does not mean that you have cancer - many other things cause these signs and symptoms, too. If you have any of these symptoms and they last for a long time or get worse, please see a doctor to find the cause.
Some general signs and symptoms associated with, but not specific to, cancer include: