Japan's correctional facilities have had trouble securing enough doctors to examine inmates, as medical students tend to favor working at private-sector hospitals that pay more and offer better opportunities to learn about advanced medical technology.
The Justice Ministry, which oversees the medical officers at prisons and juvenile reformatories, is making efforts to attract more students to the job, including legislation to improve the working conditions at penal institutions.
Reflecting the aging population itself, nearly 70 percent of inmates are elderly and affected by diseases, according to the ministry.