ABOUT HALF of all suicides in prisons across the country take place among the 5 or 6 percent of prisoners held in solitary confinement, a measure of the devastating toll exacted by isolating inmates, often for 22 hours a day, from social interactions — and often from basic health and other services. For prisoners who are deaf, blind or otherwise disabled, the damage inflicted by solitary confinement can be, and often is, shattering.

A new report from the American Civil Liberties Union paints a stark picture of the ghastly harm done by isolating prisoners with physical disabilities, a practice that occurs across the country not only in serious disciplinary cases, but often when inmates disobey routine orders or keep a messy cell. In some cases, disabled prisoners are locked away in solitary, in cells no bigger than a parking space, simply because regular cells are unavailable, or to protect them from other inmates.

In solitary confinement, disabled and other prisoners not only are denied routine human interaction but also can be denied showers, phone calls, visitation and clean clothing. It is little surprise that a United Nations report concluded that solitary confinement can be tantamount to torture and urged banning it in all cases beyond 15 days.

If only that were the case in American prisons, where on any given day 80,000 to 100,000 inmates are in solitary confinement. Of that number, data are sketchy on the numbers who have disabilities. Some big prison systems, such as Illinois’s, do not even bother counting, which in itself is a disgrace. Still, disabled people are incarcerated at disproportionate levels; at least a quarter of inmates in state prisons report some form of hearing, visual or physical impairment, according to the ACLU study.

In its investigation, the ACLU found instances in solitary confinement of physically disabled inmates deprived of wheelchairs, physical therapy, exercise and prescription medication. It found sight-impaired inmates from whom Braille materials and text-to-audio devices were withheld. It found hearing-impaired inmates who lacked access to sign-language interpreters.

One inmate in a New York state prison, Mark Gizewski, born with severe disabilities resulting from Thalidomide, a drug taken by some pregnant women, alleged in a 2014 lawsuit that he had been denied medications to ease his chronic pain and that in solitary confinement he had been denied access to a shower for nearly a week and necessary implements to clean himself.

The result of such neglect is that some former inmates are even more disabled when they leave prison than when they entered, and consequently even less able to care for themselves and lead independent lives.

It is not clear whether such cruel and degrading neglect is the norm in American prisons, or what is the frequency with which it occurs, since corrections departments are so cavalier in collecting and monitoring pertinent data. What is clear is that solitary confinement is an inhumane form of incarceration, and even more so for prisoners with physical disabilities. It should be used sparingly; too often, it is not.