Kidney cancer in early stages does not normally cause significant signs or symptoms, according to UCLA Health and American Cancer Society. Kidney cancer may grow very large and cause no pain. Sometimes a small amount of blood may be found in the urine, but there are many causes for this.
Often kidney cancer is found by accident during an MRI or CT scan for another illness, notes the American Cancer Society. An ultrasound can find kidney cancer in some cases but cannot detect all early kidney cancers.
Some symptoms of kidney cancer in later stages include flank pain, an abdominal mass and anemia, states UCLA Health. Unexplained fever, rapid or unexplained weight loss, and fatigue are also symptoms that may be related to cancer.