Bladder cancer is not contagious, so there is no need to worry about that. Bladder cancer occurs when there is a cancerous transformation of bladder tissue, leading to the formation of bladder tumors. If the tumors are malignant, they are generally termed bladder cancer. Causes of bladder cancer can include long-term exposure to certain carcinogens, such as occupations involving dyes, leather, or paintwork. Another carcinogenic factor is smoking, which is related to about one-third of bladder cancer cases. Chronic infection or prolonged irritation by foreign bodies can also increase the risk of bladder cancer, as seen in cases with bladder stones, bladder diverticula, or chronic cystitis.