An aging population in general coupled with mandatory sentencing laws has caused an explosion in the number. This is an expensive proposition for the American correctional system. A substantial reason for this increased cost is the increased medical attention people tend to require as they grow older. Prisons that rely on prison industry to subsidize the cost of operations find that elderly inmates are less able to work than their younger counterparts. There is also the fear that younger inmates will prey on elderly ones. This phenomenon has caused the federal prison system and many state systems to rethink the policies that contribute to this "graying" of correctional populations.
Substantial growth has also been seen in the number of inmates that are ill. Arthritis and hypertension are the most commonly reported chronic conditions among inmates, but more serious and less easily treated maladies are also common. Many larger jails and prisons have special sections devoted to inmates with medical problems. In addition to the normal security staff, these units must employ medical staff. Recruiting medical staff that are willing to work in confinement with inmates is a constant problem for administrators.
According to many critics of mental health in America, the number of mentally ill inmates has reached crisis level. There has been explosive growth in the incarceration of mentally ill persons since the deinstitutionalization movement of the 1960s. As well-meaning people advocated for the rights of American's mentally ill, they fostered in a sinister unintended consequence: As mental hospitals closed, America's jails became the dumping ground for America's mentally ill population. This problem was exacerbated at the federal level by the passage of the Community Mental Health Act of 1963, which substantially reduced funding of mental health hospitals. With state hospitals gone or severely restricted, communities had to deal with the issue of what to do with mentally ill persons. Most communities responded with the poor solution of criminalizing the mentally ill.