Underpads, also known as incontinence pads or bed pads, are absorbent sheets designed to protect surfaces from leakage of bodily fluids, such as urine or blood. They are typically placed underneath patients who may experience incontinence, during medical procedures, or in situations where protection of bedding or furniture is necessary. Underpads are made of soft, waterproof materials on one side to prevent leakage and often have an absorbent core to contain fluids, providing comfort and hygiene.