Urine with an unusual odor may be caused by bladder cancer, but the presence of an odor alone cannot be used to diagnose bladder cancer. Clinically, urine with an odor is commonly associated with urinary tract infections, as patients with such infections tend to have a higher amount of inflammatory secretions in their urine. Additionally, patients with urinary tract infections may lose some body water through sweating, leading to more concentrated urine, which can increase the odor. Bladder cancer patients are more susceptible to urinary tract infections, so they may also experience odorous urine. Clinically, bladder cancer is diagnosed through a combination of the patient's symptoms and supportive diagnostic tests. In the early stages of the disease, bladder cancer typically presents as painless hematuria (blood in the urine) that persists for an extended period. A routine urinalysis can be performed to check for elevated red blood cells in the urine. If bladder cancer is suspected, a cystoscopy can be conducted to identify any masses in the bladder and take biopsy samples for pathological examination. The presence of tumor cells in these samples generally confirms a diagnosis of bladder cancer.