The most common sign of bladder cancer is hematuria or blood in the urine, which will turn the urine rust or red in color. Other signs of bladder cancer may include pain during urination and frequent urination. Most patients with bladder cancer do not have symptoms other than hematuria. Unfortunately, most bladder cancers are not diagnosed until they have become very large. As a result, research is ongoing in order to develop urine tests that would enable earlier detection of bladder cancer when it is small and more easily treated.