By Melanie Evans

In western Puerto Rico, Oscar Corzo, a New York physician, was treating a woman for her chronic illnesses this month when he noticed a group of her neighbors had gathered to ask for help.

“Almost kind of organically, there was a waiting room,” said Dr. Corzo, who stayed on the woman’s porch for two hours treating her neighbors. “It really struck me because it told me what need there was.”

Two months after Hurricane Maria tore across the island, Puerto Rico’s health-care system is still struggling. Storm damage and power outages remain problems especially in rural areas where access is still difficult, say medical volunteers and relief workers who have worked on the U.S. territory in recent weeks.

In the mountainous central region of Utuado, Catherine Trossello, a nurse practitioner with Callen-Lorde Community Health Center in New York, worked a few weeks ago with a local health-care provider who was trying to track down patients he hadn’t seen since the storm. He made house calls. She set up a walk-in clinic in another part of town he couldn’t reach.

“People are on foot, going door to door, doing the best they can, but the whole network is so disrupted,” Ms. Trossello said. “Everybody’s trying so hard. But you can only walk so many miles in a day and knock on so many doors at a time.”

Recovery from the most powerful storm to hit the island in almost a century is halting at best. Half of Puerto Rico’s electric grid remains down, leaving many of the island’s 3.4 million residents exposed to the heat and unable to keep food or medicines cool without generators. Telephone service remains spotty and travel can be treacherous, exacerbating isolation.

Most Puerto Rican hospitals have regained power, though the island’s grid remains shaky and generators still keep one in five hospitals running, according to recent Federal Emergency Management Agency data. Seventeen hospitals lacked phone service, FEMA said.

Puerto Rico’s network of more than 90 largely rural federally funded primary care clinics have mostly reopened, but half remain on backup generators, limiting some services, said Katia Leon, deputy director of an association representing the clinics.

But the overall conditions, especially the absence of power, have exacerbated illnesses such as diabetes and heart disease with potentially life-threatening consequences, said medical volunteers working with the nonprofit Americares, which has hired nurses and organized pop-up clinics in western and central Puerto Rico. Lack of clean water has led to skin rashes and gastrointestinal illnesses, they said. Mold flourishing in storm-damaged buildings has made it harder to breathe for others.

Federally operated health-care shelters and temporary emergency rooms have seen a stream of chronically ill patients following an initial wave of those who suffered storm-related injuries, which is typical after disasters, according to the U.S. Department of Health and Human Services.

But unlike other disasters, chronically ill patients in who lack oxygen or dialysis are staying longer under federal care in Puerto Rico, because those life-saving medical supplies can’t be found elsewhere, according to HHS.

Americares has set up clinics in abandoned gas stations and empty bus terminals around the countryside to offer primary health services to rural communities.

Some residents had gone without medication or basic medical care since Maria hit, said doctors with the MediSys Health Network in New York who returned Nov. 8 after two weeks of working in Puerto Rico. Many residents had unhealthy blood pressure or blood sugar after going without daily medication, which put them at risk for heart attack and stroke.

On house calls in rural Puerto Rico, medical teams met residents in need of emergency care after going too long without help, including one man without phone service who had dangerously low blood pressure and rectal bleeding, said MediSys physician Celine Thum.

Raul Pineda, a medical team coordinator for Americares, which set up a pop-up clinic in Vieques last week, said a diabetic man there who had gone without insulin since the storm had to be airlifted to the main island for treatment last week. The man had two toes amputated, he said.

More than 700 people have sought care in the last month from clinics like the one in Vieques, an Americares spokeswoman said, many of whom hadn’t seen a doctor since Maria. The nonprofit has so far shipped $32 million in medications and other supplies to the island. That compares with $18 million of medicine and supplies Americares shipped to Haiti after Hurricane Matthew.

After Hurricane Maria hit, Felicita Dones, 89, could no longer stay in her nursing home in Juncos, in the eastern part of the island, because of a loss of power and water.

Ms. Dones, who has a variety of medical issues including glaucoma, blindness, high blood pressure and circulation problems, wasn’t getting adequate care on the island. So her daughter, Petra Seda, who lives in Orlando, Fla., decided she had to bring her mother to the mainland. But that too has challenges, like enrolling Ms. Dones in a Medicare plan and trying to secure her a cornea procedure.

“It’s difficult,” Ms. Seda said. “She doesn’t accept having to live in these circumstances.”