An inmate at a federal prison in Oregon faked a suicide attempt to obtain medical treatment for a serious infection because health care staffing levels were so low that patients were forced to wait days, or even weeks, for basic care, an independent watchdog found.

The work force shortages at the prison, Federal Correctional Institution, Sheridan, reflect a broader staffing crisis at dozens of facilities run by the Bureau of Prisons, according to a report released Wednesday by Michael O. Horowitz, inspector general of the Justice Department. It has spurred long waiting lists for essential medical and dental services, mental health care and drug treatment at Sheridan, mirroring similar problems at federal facilities across the country.

The minimum- and medium-security prison, just outside the state capital Salem, is emblematic of the worsening conditions at the federal prisons bureau, which operates more than 120 facilities — many in need of serious repairs and struggling to fill hundreds of high-stress, relatively low-paying jobs.

“When we go in, we are getting staff telling us, in a very straightforward way, how concerned they are about what’s going on at their facilities,” Mr. Horowitz said in an interview. “We heard repeatedly from staff, including corrections officers, who were so exhausted and so understaffed they couldn’t do their jobs.”

A Bureau of Prisons spokeswoman did not immediately respond to a request for comment.

Investigators made two unannounced inspection visits to Sheridan in November and December 2023, when they found a widespread lack of services intended to address the fundamental needs of nearly 1,500 male prisoners in three different divisions. They also uncovered significant gaps in security caused by a concurrent shortage of corrections officers.

Most alarming was a growing backlog of diagnostic tests. Inspectors found that the institution had a backlog of 725 orders for blood draws and urine samples, along with 274 pending X-ray orders. The situation caused “medical conditions to go undiagnosed,” the report said, and an on-site physician acknowledged that the backlog prevented him from monitoring the liver and kidney function of patients who had two of the most common ailments found among incarcerated people, diabetes and hepatitis C.

Nine out of 27 medical staff positions were unfilled at the time of the inspections, a 33 percent vacancy rate. In the substance abuse treatment unit, 11 out of 16 counselor positions were unfilled.

That was particularly problematic at Sheridan, which had designated for 70 inmates transferred from other lockups a residential drug abuse treatment program — a critical service for inmates eligible for expedited release under bipartisan prison changes enacted during the Trump administration as part of the First Step Act.

A few days after the investigators left the facility, the bureau transferred all of those prisoners to other facilities, said Mr. Horowitz, adding that the staffing issues severely hobbled prisoners’ access to programs that could be used to grant them earlier releases under the act.

But one incident, above the others, shocked investigators.

One inmate who had been living in the prison’s segregated housing unit had a badly ingrown hair on his face that had become so infected his face was extremely red and swollen. When his repeated requests for care were ignored, he “placed a fabric noose around his neck” in a feigned suicide attempt, knowing that officers would have no choice but to respond swiftly, according to the report.

He quickly admitted to the ruse and was rushed to the medical unit. But by this point, the infection was serious enough to require a five-day hospitalization outside the prison, Mr. Horowitz’s team found.

The staffing shortages were as bad in other areas of care. The prison’s bare-bones dental unit had a backlog of more than 350 patients. Many had been waiting at least two years for basic services like teeth cleaning, cavity removal and root canals.

Sheridan, like many other federal facilities, also has significant issues with its infrastructure and other core services. The inspector general found leaky roofs, substandard food services and smuggled drugs, among other problems.

In a similar unannounced inspection a year ago, investigators discovered many of the same problems at the federal women’s prison in Tallahassee, Fla.: moldy bread on lunch trays, rotting vegetables, breakfast cereal and other food crawling with insects or rodents, cracked or missing bathroom and ceiling tiles, mold and rot almost everywhere, leaky roofs stoppered with plastic bags, windows blocked with feminine hygiene products to keep out the rain and loose ventilation covers that could hide contraband and weapons.

In testimony last year before a subcommittee of the House Judiciary Committee, the director of the Bureau of Prisons, Colette S. Peters, heralded recent gains in employee retention. But she said that staffing levels in some key departments, especially in medical units, were still half of what they needed to be.

The bureau’s unmet infrastructure needs are just as dire. Ms. Peters said her team was surveying the 300-plus prison buildings operated by the bureau, but she estimated that $2 billion was needed to clear the backlog of repairs and renovations identified as urgent.

In his proposed budget for the 2025 fiscal year, President Biden has slated about $200 million toward improving prison infrastructure.