In several of the hospitals still functioning in Gaza, nurses are fainting from hunger and dehydration. Managers often cannot provide meals for patients or medical staff. Doctors are running low on formula for newborn babies, in some cases giving them water alone.

And at least three major hospitals lack the nutritional fluids needed to properly treat malnourished children and adults.

Those scenes were described in interviews starting Friday with seven doctors — four from Gaza, and three volunteers from Australia, Britain and the United States. All of them worked this past week in four of the territory’s main hospitals.

After months of warnings, international agencies, experts and doctors say starvation is now sweeping across Gaza amid restrictions on aid imposed by Israel for months. At least 56 Palestinians died this month of starvation in the territory, nearly half of the total such deaths since the war began 22 months ago, according to data released on Saturday by the Gaza Health Ministry.

As starvation rises, medical institutions and staff, already struggling to treat war wounds and illness, are now grappling with rising cases of malnourishment.

Weak and dizzy, medics are passing out in the wards, where colleagues revive them with saline and glucose drips. Persistently short of basic tools such as antibiotics and painkillers, doctors are also running out of the special intravenous drips used to feed depleted patients.

In all four hospitals, the doctors described how they are increasingly unable to save malnourished babies and are instead forced to simply manage their decline. The babies are too weak to be flooded with nutrients, which could overload their system and cause them to suffer “refeeding syndrome,” which could kill them.

In some cases, the fluids that the doctors can safely give to the babies are not enough to prevent them from dying.

“I have seen ones that are imminently about to pass away,” said Dr. Ambereen Sleemi, an American surgeon who has been volunteering since early July at the Nasser Hospital in southern Gaza. The babies were brought to the hospital “starving and malnourished,” Dr. Sleemi said in a phone interview on Friday, “and they haven’t been able to get them back from the brink.”

Dr. Nick Maynard, a British surgeon who volunteered at the same hospital until Wednesday, described the shock of seeing a skeletal infant who looked only days old, but was in fact seven months.

“The expression ‘skin and bones’ doesn’t do it justice,” Dr. Maynard said in a phone interview on Friday. “I saw the severity of malnutrition that I would not have thought possible in a civilized world. This is man-made starvation being used as a weapon of war and it will lead to many more deaths unless food and aid is let in immediately.”

Asked for comment, COGAT, the Israeli military department that oversees aid to Gaza, said it “continues to work in coordination with international actors to allow and facilitate the continued entry of humanitarian aid into the Gaza Strip, in accordance with international law.” Late on Saturday night, the Israeli military began to drop airborne aid over northern Gaza, and said it would pause its military activity for several hours day in key areas to make it easier to deliver aid by land.

One-third of Palestinians in Gaza are forced to go without food for days in a row, the World Food Program said recently. Of the young children and pregnant women treated at clinics run by Doctors Without Borders in Gaza, roughly one-fourth are suffering from malnutrition, the medical aid group said last week.

Doctors say that many other people have likely died from different conditions and injuries that could have been cured or healed if the victims had not been so weakened by malnourishment. Starvation is causing more mothers to suffer miscarriages or give birth prematurely, to malnourished babies with weakened immune systems and medical abnormalities.

“The result is a rise in infections, dehydration and even immune collapse in infants,” said Dr. Hani al-Faleet, a pediatric consultant at Al-Aqsa Martyrs Hospital in central Gaza. “The immediate cause of death in some of these cases is simple: The baby doesn’t get enough to eat, and neither does the mother.”

Starvation has risen sharply since Israel’s total blockade on food aid to Gaza between early March and late May, doctors and rights groups say. While Israel has since allowed food in, it introduced a new method of distribution that is flawed and dangerous, making it almost impossible for Palestinians to find food safely or affordably.

Before March, food handouts were mainly distributed under a U.N.-led system from hundreds of points close to where people lived. Now, they are supplied from a handful of sites run by Israeli-backed private American contractors that, for most Palestinians in Gaza, can be reached only by walking for miles through Israeli military lines.

Israeli soldiers have killed hundreds of people walking these routes, turning the daily search for food into a deadly trap.

Some food is still available from shops in Palestinian-run areas, but only at astronomic prices that are unaffordable to the largely unemployed civilian population. A kilogram, or 2.2 pounds, of flour costs up to $30, and a kilogram of tomatoes costs roughly $30; meat and rice are largely unavailable on the open market.

That has forced many Palestinians to routinely choose between two often fatal options: risk death by starvation, or risk death by gunfire to reach food aid sites that are likely to have run out of supplies by the time many arrive.

Israel publicly says the new aid system is necessary to prevent Hamas from stealing the aid. But Israeli military officials have acknowledged to The New York Times that they have no proof that Hamas has systematically stolen food supplied by the United Nations, the main provider of aid to Gaza during most of the war. Israel says that its soldiers have fired “warning shots” to quell unrest along the roads leading to the aid sites. Dr. Maynard and Dr. Sleemi described injuries that indicated soldiers had systematically fired at people’s torsos.

Israel also blames the United Nations for failing to deliver enough food to alleviate the situation. Israel said on Saturday that it had destroyed up to 100 truckloads of food in recent months because aid groups could not distribute the food before it passed its use-by date. U.N. officials say that Israeli restrictions have made it difficult to send convoys through an active war zone.

The food shortages add another challenge to an already very difficult environment for doctors.

“Some staff members have collapsed in operating rooms. Others have fainted in emergency wards because they have not received any proper food,” said Dr. Mohammad Abu Salmiya, the director of Al-Shifa Hospital in Gaza City. “The burden on them is immense.”

Salam Barghouth, a 3-month baby girl treated for malnutrition this week at Al-Aqsa Martyrs Hospital in central Gaza, is among the youngest Palestinians failed by the new aid distribution system. Her mother, Hanin Barghouth, 22, is too weak to walk to the new distribution sites. Her father, Akram Barghouth, 27, has never managed to reach the sites before the aid runs out, Ms. Barghouth said.

Like most Gazans, the parents are jobless, rely on donations from relatives and friends and said they survive mostly on falafel balls that cost roughly 10 times their prewar price.

As a result, Ms. Barghouth regularly skips meals and says she has lost 29 pounds, a fifth of her body weight, since the start of the war. She cannot produce enough breast milk to feed Salam, who was born on April 21, after Israel started the blockade.

At Salam’s birth, according to Dr. al-Faleet, her doctor, she weighed roughly 6.6 pounds. Three months later, she weighs only 8.8 — at least three pounds underweight, the doctor said.

“I’m breastfeeding her as much as I can, and when I can’t, I give her formula — but that’s only when I have it,” Ms. Barghouth said. She is reaching the end of a container of formula that she said cost roughly $120, approximately two and a half times the amount it costs outside Gaza.

“She came into the world during a war,” Ms. Barghouth added, “and I’m fighting every day to keep her alive in it.”

While Salam Barghouth can still access medical support in central Gaza, other starving children farther to the north are struggling to find it because aid groups have found it harder to bring supplies to them.

One of them is Yazan Abu al-Foul, 2, a child living with his family in a damaged building beside a beach in Gaza City. His ribs, spine and hip bones jut from his body. An aunt, Riwaa Abu al-Foul, said Yazan’s family cannot find enough food to feed him and hospital staff in his area have told them that they cannot provide him with inpatient care.

“They told us there is a shortage of materials and equipment,” Ms. Abu al-Foul said in a phone interview on Saturday.

Doctors at hospitals in northern, central and southern Gaza described similar hardships in interviews on Friday and Saturday.

“There are no nutritional supplements, no vitamins, no premature infant formula, no amino acid intravenous solutions — nothing,” said Dr. Abu Salmiya from Al-Shifa Hospital. “Their bodies need these basics, and without them they will die.”

Aaron Boxerman contributed reporting.