Kidney cance r- Causes, Systems When to seek a doctor and Risks

Kidney cancer is cancer that originates in the kidneys. Your kidneys are two bean-shaped organs, each about the size of your fist. They're located behind your abdominal organs, with one kidney on each side of your spine.

In adults, the most common type of kidney cancer is renal cell carcinoma. Other less common types of kidney cancer can occur. Young children are more likely to develop a kind of kidney cancer called Wilms' tumor.

The incidence of kidney cancer seems to be increasing. One reason for this may be the fact that imaging techniques such as computerized tomography (CT) are being used more often. These tests may lead to the accidental discovery of more kidney cancers.

Kidney cancer rarely causes signs or symptoms in its early stages. In the later stages, kidney cancer signs and symptoms may include:
Blood in your urine, which may appear pink, red or cola colored
Back pain just below the ribs that doesn't go away
Weight loss
Fatigue
Intermittent fever
When to see a doctor

Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.
It's not clear what causes renal cell carcinoma. Doctors know that kidney cancer begins when some kidney cells acquire mutations in their DNA. The mutations tell the cells to grow and divide rapidly. The accumulating abnormal cells form a tumor that can extend beyond the kidney. Some cells can break off and spread (metastasize) to distant parts of the body.


Kidney cross section

Causes
It's not clear what causes renal cell carcinoma. Doctors know that kidney cancer begins when some kidney cells acquire mutations in their DNA. The mutations tell the cells to grow and divide rapidly. The accumulating abnormal cells form a tumor that can extend beyond the kidney. Some cells can break off and spread (metastasize) to distant parts of the body.

Factors that can increase the risk of kidney cancer include:
Older age. Your risk of fkidney cancer increases as you age.
Smoking. Smokers have a greater risk of kidney cancer than nonsmokers do. The risk decreases after you quit.
Obesity. People who are obese have a higher risk of kidney cancer than do people who are considered average weight.
High blood pressure (hypertension). High blood pressure increases your risk of kidney cancer.
Treatment for kidney failure. People who receive long-term dialysis to treat chronic kidney failure have a greater risk of developing kidney cancer.
Von Hippel-Lindau disease. People with this inherited disorder are likely to develop several kinds of tumors, including, in some cases, kidney cancer.
Hereditary papillary renal cell carcinoma. Having this inherited condition makes it more likely you'll develop one or more kidney cancers.

Source: Mayoclinic