A bathtub with a door, or a walk-in bathtub, is for people who find it difficult to enter and exit a traditional bathtub, such as the elderly or people with disabilities. A walk-in bathtub is also for people who wish to have a spa or whirlpool experience but do not have the space for a traditional whirlpool bath.
Though the traditional bathtub usually has a 15-inch-high wall to step over to enter the tub, a walk-in tub only has a 3- to 7-inch-high threshold.
Walk-in bathtubs are taller than usual bathtubs. Their floors are slip resistant, and they have built-in seating, grab bars and other features such as hand-held showers, anti-scald valves and in-line heaters. The doors are watertight and open either on the side of the tub or at the front. Many walk-in tubs feature faucets for quick filling and drains that are pump-assisted to allow water to drain quickly.
Some walk-in bathtubs come with hydrotherapy and aerobath therapy jets, chromatherapy and aromatherapy. Aerobath therapy tubs use air jets, while hydrotherapy baths use water jets. Tubs that have chromatherapy use lighting to calm the bather, while tubs that use aromatherapy have diffusers that disperse pleasing scents into the air for the same purpose.