Your kidneys remove waste from your blood and regulate a healthy balance between water, sodium and minerals in your bloodstream.

"Kidneys filter intoxicants, drugs and waste products out of your blood," says Dr. Scott Cheney, a Mayo Clinic urologic surgeon. "We would actually die within about a week without having good kidney function."

Poor kidney function could mean kidney cancer, but signs or symptoms are rare in its early stages. Patient are sometimes informed about kidney cancer tumors when they are discovered during CT scans or other imaging techniques for unrelated ailments.

In this Mayo Clinic Q&A podcast, Dr. Cheney discusses different types of kidney cancers, how smoking can affect the kidneys and why treatment usually involves surgery.