This resource is relevant to criminalized populations including sex workers and people who use drugs. It is about the excessive use of pretrial detention—the arrest and incarceration of people who have not yet been convicted of any crime—which poses a great risk to public health and human rights, requiring urgent attention from health and prison reform advocates alike. Globally, almost 10 million people yearly spend time in detention without appearing before a judge. Pretrial detainees account for over a third of all the people in jails and prisons around the world, and are frequently held in overcrowded, substandard conditions without medications, medical treatment, or any measures for infection control. The health risks associated with pretrial detention affect not only those detained but also societies at large, as people cycle out of prison and pretrial detention and back into the community.