Many prisons suffer from a shortage of low and medium security hospital beds. Even following diagnosis, many mentally ill people are left in prison rather than receiving hospital care. This lack of service is not always deliberate, but can be due to a lack of medical facilities for prisoners, as in the UK. There, mentally ill prisoners overcrowd the prisons because there are not enough hospital beds to receive them. As it is illegal to treat them for serious mental illness outside a hospital, they must not be treated until a bed becomes available.
Of 7000 mentally ill prisoners in the UK, 35% of the women and above 20% of young men cannot be treated due to a shortage of secure hospital space. In 1995, 800 secure beds were in use and 1000 more were needed but were not available for prisoners.