There are many types of kidney diseases. A kidney disease makes the kidneys unable to work perfectly but they do work in part. People can have mild kidney failure and have no symptoms. As long as it does not become worse, people may not even know they have it. "Severe" kidney failure means "very" bad failure. The kidneys do not work very much at all. People with severe kidney failure "always" have symptoms. They may need special care from doctors. 