NASHVILLE — Mary Howard, a dishwasher with no health insurance, has never had Covid-19. But the coronavirus, she said, caused her life to spiral over the past two years.

Friends died from it. Ordinary parts of her day, like riding the bus, felt perilous. The restaurant where she worked closed temporarily, and she fought depression and high blood pressure, seeking care in the emergency room because in-person appointments were hard to come by as the pandemic raged.

She turned for help to Nashville General Hospital. The lone public safety-net hospital in a city with a booming health care industry, it has provided care to multitudes of poor and uninsured people throughout the pandemic and for more than 130 years.

Now, the end of federal programs that paid for Covid care for the uninsured and helped stabilize hospital finances during the pandemic is threatening a new kind of crisis for people like Ms. Howard and the providers that care for them. Billions of dollars in aid not only guaranteed that uninsured Covid patients would not face medical bills during the pandemic but also offered a lifeline for financially stressed institutions like Nashville General that provide extensive uncompensated care for the poor.

The infusion of aid is ending at a time when hospitalizations from Covid are receding, but as safety-net providers are facing tremendous unmet needs from patients who have delayed care for chronic conditions and other health problems even more than usual during the pandemic.

“Their margins are slim to begin with,” Beth Feldpush, the senior vice president for policy and advocacy at America’s Essential Hospitals, which represents safety-net hospitals, said of the institutions. She added that some were already having a “more difficult time bouncing back operationally and financially.”

Nashville General has seen an average of just one Covid patient a week recently. But its doctors and nurses say that a wide range of health problems that worsened during the pandemic are now overwhelming the hospital.

As he prepared to clip an uninsured patient’s worsening fungal toenails, Dr. Andrew Pierre, the hospital’s podiatrist, said the range of unchecked problems had expanded in his practice: bunions, flat feet that need reconstructive surgery, a surge in diabetic wounds.

Dr. Eric Neff, an orthopedic surgeon, said patients were afraid to visit the hospital during much of the pandemic and often had trouble finding transportation when they did. The consequences were dire: People waited six months to seek care for a broken wrist or ignored a torn rotator cuff, making it harder for him to fix their injuries.

“It’s horrible,” he said.

Dr. Philip Elizondo, his orthopedic colleague, said the hospital had to cancel minor surgeries for health problems that subsequently ballooned. One uninsured woman he treated had torn her meniscus, lost her job and lost her house. Dr. Elizondo said he could have performed a 20-minute surgery if the patient had been able to seek care immediately, but instead her injury went untreated and got worse.

Dr. Richard Fremont, a pulmonologist, said that he had treated dozens of Covid patients over the past two years, but that patients with other health conditions, such as chronic asthma, had more often needed oxygen. Because uninsured patients cannot get short-term home oxygen therapy, he sometimes keeps those who need it in the hospital for days or weeks.

The crisis of the uninsured is especially acute in Tennessee, which has one of the highest rates of hospital closures in the country and is among a dozen states that have chosen not to expand Medicaid to cover more low-income adults under the Affordable Care Act. Roughly 300,000 people in the state fall in the so-called coverage gap, meaning they are ineligible for either Medicaid or discounted health insurance under the Affordable Care Act despite having little to no income.

John Graves, a health policy professor at Vanderbilt University School of Medicine, said the influx of relief funds during the pandemic had allowed something akin to a “universal coverage system within a system,” granting coverage to everyone who got Covid. Now, he said, hospitals and patients are back to facing prepandemic pressures — and will face even more once the federal government ends the public health emergency, which has temporarily increased Medicaid and Medicare reimbursements.

The federal Provider Relief Fund offered hospitals an early lifeline in the pandemic by providing tens of billions in direct funding, although the money was steered inequitably, said Jason Buxbaum, a Harvard doctoral student who has written about the program.

Separately, the Covid-19 Uninsured Program provided more than $20 billion in reimbursements to roughly 50,000 hospitals, clinics and other providers for testing, vaccinating and treating the uninsured, including nearly $8 million to Nashville General. A pandemic relief package that has stalled in the Senate will most likely not replenish the fund, leaving providers on the hook and making reimbursements during future Covid waves unlikely.

“The safety net has been disinvested in, and has been a political football, for a decade,” said Michele Johnson, the executive director of the Tennessee Justice Center, a legal aid group that helps poor Tennesseans. The influx of pandemic aid, she added, “kind of covered up this thing that was barely hanging on the ropes; it put some rouge on the corpse.”

Hospitals like Nashville General have disproportionately cared for communities hit hardest by the virus. They have also not been performing as many surgeries and procedures during the pandemic that could subsidize the cost of treatment for people seeking delayed care, according to Ms. Feldpush of America’s Essential Hospitals. That could mean having to pare back services further, she said, such as scaling back hours in an outpatient clinic or delaying opening a new clinic altogether.

Hospitals and community clinics in Nashville are unlikely to benefit from Medicaid expansion any time soon. State lawmakers last year rejected what could have amounted to hundreds of millions in savings over two years from an expansion offered under President Biden’s $1.9 trillion stimulus package.

And the Biden administration’s social policy bill, which would have provided poor adults in states that did not expand Medicaid with access to free coverage, appears all but dead.

Nashville General’s finances improved during the pandemic. Even though the number of inpatients declined, revenues grew as those who were hospitalized stayed longer and patients were sicker overall, in part because of Covid. The hospital received roughly $10 million in federal stimulus funding, helping it break even, hospital officials said.

Losing the federal funds will be “hard to contend with,” said Dr. Graves, the Vanderbilt health policy expert, not least because the cost of labor has surged.

The stimulus was an “answer to prayers,” said Brian Haile, the chief executive of Neighborhood Health, a network of community health clinics in Nashville that serve the uninsured. The money covered administrative fees for vaccines and testing for uninsured patients across the city, helping relax fears about surprise bills. The funds also allowed the clinics to compete for medical workers who might have been drawn to higher-paying jobs elsewhere in town.

As the cost of contract labor rose substantially, Nashville General grappled with the costs of hiring nurses and respiratory therapists. The hospital had dozens of nurse openings before the pandemic and struggled to retain its staff, as pay for travel nurses skyrocketed and private hospitals looked to add to their ranks with offers of higher salaries.

Rates for nurses and respiratory therapists, critical positions for treating Covid patients, remain high, hospital executives said. Drug prices are also high, they said — another source of financial anxiety after the lapse in federal funds.

Dr. DeAnn Bullock, Nashville General’s chief medical officer and its emergency department medical director, said the unit conducted between three and 10 psychiatric evaluations each day — more than before the pandemic — in a hospital that does not have a psychiatric ward.

“From kids to adults to seniors,” she said. “Not only do you have a higher incidence and prevalence that’s now out there, I think that people are now more able to talk about it, feel comfortable saying: ‘I have this. I need some help.’”

The hospital has also seen more diabetic ketoacidosis, often the result of poor diabetics fearful of drug costs trying to stretch out their medications, doctors said. Patients have skipped colonoscopies and mammograms, doctors said, leading to more advanced cancers.

Sick with Covid in the winter of 2020 as the coronavirus ravaged Tennessee, Randall Aikens appeared lifeless to his family. He arrived at Vanderbilt University Medical Center, across town from Nashville General, with plunging odds of survival.

But as Mr. Aikens stabilized, doctors discovered a different concern, one they believed was greater than the virus, his mother, Gwendolyn, said. He had undiagnosed diabetes, and his blood pressure and blood glucose levels were alarmingly high. Uninsured and on food stamps, he now visits Nashville General for primary care appointments to keep a close watch on his diabetes.

For John Spence, a patient in Nashville General’s orthopedic unit who works at a cleaning service, not having health insurance during the pandemic and often working seven days a week made it harder to manage his diabetes, high blood pressure and the sometimes long list of medications he takes, he said after a recent checkup. An infection and abscess he developed during the pandemic almost turned fatal after he discovered fluid leaking out of his foot. Surgeons at the hospital had to amputate the lower part of his left leg last fall.

“We see a lot of putting off, putting off, because it’s like: ‘Maybe we can do it tomorrow. Maybe we can do it the next day, or maybe it’ll just go away,’” said Dr. Rosalena Muckle, an internal medicine physician.

Ms. Howard, the dishwasher, said her frustrations getting and affording health care were adding up. Her ailments were not improving. After a recent primary care appointment, she wondered aloud how she would come up with the $10 for her visit. “I don’t want to just be seen or heard,” she said. “Without any money, it’s hard.”

She said she still had dreams — to become a medical assistant, or a bus driver for the elderly.

“To take care of people,” she said.