Painless blood in the urine (hematuria) is the most common symptom. It eventually occurs in nearly all cases of bladder cancer. In the majority of cases, the blood is visible during urination. In some cases, it is invisible except under a microscope, and is usually discovered when analyzing a urine sample as part of a routine examination.

Hematuria does not by itself confirm the presence of bladder cancer. Blood in the urine has many possible causes. For example, it may result from a urinary tract infection or kidney stones rather than from cancer. It is important to note that hematuria, particularly microscopic, might be entirely normal for some individuals. A diagnostic investigation is necessary to determine whether bladder cancer is present. Other symptoms of bladder cancer may include frequent urination and pain upon urination (dysuria).