A balloon catheter is a medical device used to treat various conditions within blood vessels or other hollow organs. It consists of a thin tube with a small inflatable balloon at its tip. When inserted into the body, the balloon can be inflated to open up narrowed or blocked passages, allowing for improved blood flow or drainage. These catheters are commonly used in procedures like angioplasty, where they help widen narrowed arteries, or in urethral catheterization to relieve urinary obstructions. Balloon catheters are designed for temporary use and are typically removed after the procedure is completed.