However, you should note that having blood in your urine does not necessarily mean that you have bladder cancer. Many other conditions can cause blood in urine. In fact, in most cases of bladder cancer, blood in the urine is so minute that you cannot see it with your eyes. The medical term for invisible blood in urine is microscopic hematuria. Visible blood in urine almost never occurs in bladder cancer.
A more valid sign of bladder cancer is actually having cancerous appearing cells in your urine. Transitional cell carcinoma is the medical term you'll hear if these cells are appear in your urine. When a positive result occurs, further testing is required.
Other, less common symptoms of bladder cancer include "irritative voiding symptoms." Irritatiive voiding symptoms include symptoms such as frequent and urgent urination. This occurs sometimes because the bladder is more irritated when bladder cancer is present.
Source: Cornell University Medical School Urology. Bladder Cancer Symptoms. Accessed 11/03/2010.