Bladder cancer is the growth of cancerous tissue in the mucous membrane within the bladder. As the cancerous tissue continues to grow, the tumor spreads into the bladder muscle, breaks through the bladder and grows into the pelvis, or metastasizes to other parts of the body through blood or lymph. Bladder cancer has its own specific type of pathology, causes and symptoms. Most bladder cancer patients may be caused by exposure to harmful substances, and long-term exposure to harmful substances can lead to abnormal changes in bladder cells. According to statistics, more than one-third of bladder cancers are caused by smoking. Occupations associated with an increased risk of bladder cancer include auto workers and jobs involving organic chemicals, and frequent exposure to aromatic amines during work is a substance that by apparently causes bladder cancer to occur. Painless hematuria is the most common manifestation of bladder cancer, with 90% of patients experiencing this symptom. It is mainly caused by vascular damage caused by the erosion of the mucosa in the bladder during the infiltrative growth of bladder cancer. Urinary frequency, urgency and difficulty in urination are also possible symptoms. There are two types of bladder cancer: 1. Non-muscle invasive bladder cancer, also known as superficial bladder cancer, occurs when the cancer cells are contained in the inner bladder and have not invaded the bladder wall. This is considered an early stage and accounts for about 70-75% of all diagnoses. 2, Muscle-invasive bladder cancer occurs when the cancer invades the bladder wall. It is considered to be the beginning of a more serious stage of bladder cancer. In some cases, muscle-infiltrating bladder cancer can also spread (metastasize) to surrounding organs or other parts of the body, which is a more serious stage. Patients who experience symptoms such as painless hematuria, frequent urination, and urinary urgency must go to the hospital as soon as possible to be alert to the appearance of bladder cancer.