ANTAKYA, Turkey — An ambulance pulled up to the cluster of red tents that now serves as the main hospital in the ruined city of Antakya, on Friday morning. It was bringing in a woman pulled from the wreck of her home after nearly 100 hours under the rubble.

Though one of her legs was fractured and she had been hit in the head by a falling concrete block, she was conscious and able to speak. She wanted to know where her two children were. But they had not yet been found.

For the doctors in the field hospital, hastily constructed in a parking lot, miracles had grown nearly routine, but there were never enough of them. As the days pass and more dead than living people are taken from the rubble, they grow rarer and rarer.

At the field hospital, 200 patients are no longer arriving every hour, as they did on Monday and Tuesday.

Yet people continued to be tugged from the debris, requiring treatment for crushed limbs, dehydration and exposure. That often meant amputation. For many pregnant women, it had meant going into trauma-induced early labor.

“If I told you what I’ve been through, what I’ve seen these last five days, maybe the movies wouldn’t seem that dramatic by comparison,” said Halil Kabadayi, 25, a nurse in the maternity ward — that is, a red tent — who had dropped everything to come from the city of Izmir, Turkey, to volunteer.

Given the extent of the destruction, the fact that Antakya has established a semi-functioning medical system is remarkable. Monday’s earthquake took out hospitals as well as homes, leaving emergency responders across 10 provinces unable to care properly at first for people crushed by collapsing buildings.

Since then, however, a new, makeshift health care system has been constructed amid the devastation by volunteers from around Turkey and the world. While the most severely wounded were sent to undamaged hospitals in other provinces for treatment, field hospitals in the heart of the earthquake zone sprung up to stabilize the newly rescued, treat more minor injuries and manage the diseases that are flaring in the disaster’s wake. Even pets rescued from the rubble were receiving volunteer medical care at a pop-up animal hospital in Antakya.

“Our work has just begun,” said Dr. Ferit Kilic, 38, an emergency-room doctor at a government hospital in Istanbul who volunteered to help on Monday. “As health teams, we’ve been here for five days with no shower, no toilet. But these aren’t important. Each life we save is important for us.”

One medical student hitchhiked 375 miles to the disaster zone as soon as he heard about the earthquake; Mr. Kilic flew in from Istanbul on a plane full of volunteer doctors and nurses. A veterinarian and her boyfriend drove in from Ankara intending to help humans, only for her to end up treating pets. An Indian maxillofacial surgeon and the rest of his army medical team set off for Turkey, one of multiple medical groups from around the world who would show up to help.

“I just heard the news and thought, I can’t stay at home,” said Mumtaz Buyukkoken, 27, a medical intern from the Turkish city of Konya. He said he had spent the days since the earthquake helping to set up a makeshift hospital in a school in the coastal city of Iskenderun, where one of two hospitals was knocked out of commission.

The emergency touched the lives of many medical professionals from the region, too, often preventing them from helping. In Pazarcik, near the epicenter of the earthquake, only five or six of the 13 members of an ambulance crew — one of just two in the town — were able to work after Monday, said one ambulance worker who had lost many relatives.

The rest had to bury family members or find new places to live.

‘’I couldn’t get back to work,” said Emre Tokgözlü, the ambulance worker. “I am only dealing with my own family since the quake.”

All week, the soundtrack of Antakya and other hard-hit cities has been the din of crisis. Helicopters carrying aid have become so commonplace people hardly look up. In the absence of electricity, thrumming generators power floodlights for the search-and-rescue teams. Ambulance sirens scream on and on, raging against traffic so impenetrable it always takes a minute for drivers to let them through.

Yet, every so often, silence falls across a street. The search-and-rescue teams call for everyone to hush, and cars turn their engines off while the searchers listen for voices under the rubble.

The sirens are a reminder that there are still people with heartbeats under the concrete. Increasingly, however, there are no voices, and the searchers find only bodies.

As the chaos and trauma calms from the early days after the disaster, it often falls to the doctors not only to treat the patients’ wounds but to try to reunite them with their scattered households, assuming they are alive: parents separated from children, children from siblings, owners from pets, and few able to find each other on their own because electricity and mobile service remain scarce.

Now, new waves of patients are creeping in: people from rural villages, stranded at the end of snowy or damaged roads, who could not reach help until now; people who were too busy searching for buried relatives or finding shelter to seek treatment for their own minor wounds; people injured while going back to unstable homes to retrieve belongings. Rendered suddenly homeless on Monday, many people had gone all week without medication for chronic diseases such as asthma, diabetes and hypertension.

Doctors in Hatay province, where Antakya is the biggest city, said they were also concerned about the health effects of sleeping for days in the cold, as many people displaced by the quake have been.

Hundreds of thousands of people were living in crowded tents without access to toilets, showers, soap or much nourishing food, and conditions were ripe for infectious diseases to spread. People were burning whatever they could find to keep warm in freezing temperatures, developing constant coughs from the acrid smoke. No toilets, not even port-a-potties, meant many people were drinking less than they should to avoid having to relieve themselves out in the open, and that was leading to dehydration, doctors said.

For everyday disease management and treatment of minor injuries, many of the newly homeless were turning to small makeshift clinics like that run by Turkey’s Communist Party on the western side of Antakya. Under a blue tarp stretched next to the ruins of a gas station, volunteers handed out donated medications, while doctors tended to Bassel al-Noun, 31, a Syrian baklava maker who had spent the last four days pulling victims from collapsed apartments. He had been too occupied to get help for his bloody left hand, which he could not move much.

Aslihan Cakaloglu, 45, one of the doctors, came to Antakya from Ankara, the capital. She and her team had been overwhelmed at first by the scale of the disaster, she said, a problem for which the only solution had been to go to work, and keep working.

“To know there are many people under the buildings who you’re not able to reach and treat, it’s very bad,” Dr. Cakaloglu said. “But now we’re organizing. It means something that we can do our jobs.”

Safak Timur contributed reporting from Gaziantep, Turkey.