Bladder cancer is a type of cancer that begins in the cells of the bladder, which is a hollow organ in the pelvis responsible for storing urine. It is the sixth most common cancer in the United States, with the majority of cases occurring in older adults. Risk factors for developing bladder cancer include smoking, exposure to certain chemicals, age, and a family history of the disease. Symptoms of bladder cancer can include blood in the urine, frequent urination, and pain during urination. Treatment options for bladder cancer vary depending on the stage and extent of the disease, and may include surgery, chemotherapy, radiation therapy, and immunotherapy. Researchers are studying new ways to diagnose, treat, and prevent bladder cancer in order to improve outcomes for patients.