KAB ELIAS, Lebanon (AP) -- Trapped in her northern Syrian village by fighting, Mervat watched her newborn baby progressively shrink. Her daughter's dark eyes seemed to grow bigger as her face grew more skeletal. Finally, Mervat escaped to neighboring Lebanon, and a nurse told her the girl was starving.
The news devastated her. "They had to hold me when they told me. I wept," the 31-year-old mother said, speaking in the rickety, informal tent camp where she now lives with her husband in the eastern Lebanese town of Kab Elias.
Her daughter Shurouk has been undergoing treatment the past three months and remains a wispy thing. The 9-month-old weighs 7 pounds (3.2 kilos) -- though she's become more smiley and gregarious. Mervat spoke on condition she be identified only by her first name, fearing problems for her family in Syria.
Her case underscored how dramatically Syrian society has unraveled from a conflict that this weekend enters its fourth year. Such stark starvation was once rare in Syria, where President Bashar Assad's autocratic state ran a health system that provided nearly free care.
That system, along with most other state institutions, has been shattered in many parts of the country where the fighting between Assad's forces and the rebels trying to overthrow him is raging hardest. The war has killed more than 140,000 people and has driven nearly a third of the population of 23 million from their homes -- including 4.2 million who remain inside Syria and 2.5 million who have fled into neighboring countries. Nearly half those displaced by the war are children.
Now aid workers believe starvation cases are increasing in besieged areas of Syria and malnutrition is spreading among the poorest Syrian refugees.
Before the conflict, doctors inside Syria would see fewer than one case a month of a child with life-threatening malnutrition, now they tell UNICEF they encounter 10 or more a week, said Juliette Touma, a Middle East regional spokesperson for the U.N. children's agency.
In Lebanon, malnutrition grew from 4.4 percent in 2012 to 5.9 percent of Syrian refugee children, according to a recent UNICEF-led survey. In all, an estimated 10,000 Syrian children in Lebanon are likely suffering malnutrition, said Dima Ousta of the International Orthodox Christian Charities, an NGO leading efforts to deal with the issue in Lebanon. UNICEF said nearly 2,000 were at risk of dying because of acute malnutrition if they weren't immediately treated.
A survey in Jordan found that 4 percent of Syrian refugee children under five needed treatment for moderate or acute malnutrition, the World Food Programme said on Monday.
Touma said UNICEF had not yet finished surveys for refugees in Turkey or inside Syria itself.
Malnutrition is the product of a series of ever-widening and interconnected problems.
Within Syria, fighting in the worst hit areas can limit access to food supplies and health care for children. There and among refugees, children are vulnerable to diarrhea and other illnesses from drinking dirty water or being exposed to sewage. Those conditions can exacerbate malnutrition and, in turn, malnourished children are less resistant to disease.
Social factors also play in. Rural Syrian women tend to marry as teenagers and rely on their mothers or other relatives to help in child-rearing. But as refugees, many lose that support network and without guidance don't know how to properly breastfeed their children -- bringing a risk of malnutrition. As refugees run out of money and struggle to find work, many mothers don't have enough to buy supplementary food.
The poverty and poor hygienic living conditions at the root of the problem are likely only to worsen as Syria's war drags on.
"Malnutrition is not an issue related to food. It's a health issue," said Zeroual Azzeddine of UNICEF.
In Lebanon, nearly one million Syrians are registered as refugees by the U.N. refugee agency. The poorest 140,000 live in 460 informal camps, where they live in poorly insulated tents with no clean running water and with sewage running down ditches between tents.
Aid workers are trying to track down the thousands of malnourished children they believe are in Lebanon.
"We need to find these children," said Ousta, whose organization treated 170 cases since August.
UNICEF is training doctors to identify malnutrition among Syrian children undergoing immunizations and other medical checks. The doctors weigh children, measure their upper-arm circumference and check their feet for water retention that can be a sign of acute malnutrition. They are on alert for mothers who say their babies are always tired, another signal.
Mervat, who lived with her family in the northern Syrian village of Tel al-Daman, was too poor to buy food for her daughter, who kept vomiting the breast milk she gave her.
She watched Shurouk shrink and her stomach bloat. But the fear of clashes between rebels and government troops kept her from reaching a doctor in the nearby city of Aleppo.
Fearing her daughter would die, she fled to Lebanon four months ago.
Now she and her husband and eight children sleep in a tiny shack of wood, cardboard and plastic, with a small heater and thin mats. Her husband, a laborer, hurt his foot and cannot work. Her older daughters decorated the tent with an old lace curtain, faded plastic flowers and a green-and-white teddy bear.
But it doesn't protect them from the icy wet cold, and Shurouk keeps falling ill. When doctors first saw her in Lebanon, she weighed 6.6 pounds (3 kilograms), climbed up to 8.8 pounds (4 kilograms) and then lost weight in a flu bout, said Maha Shoker, an aid worker monitoring her case. Shurouk remains acutely malnourished and, making her situation more precarious, she also has gall bladder stones.
Refugees must grapple with another problem. The U.N. and partner organizations only cover basic care because there's not enough money. Syrian children with illnesses sometimes fall through the gaps -- and because they are sick, they don't eat, and malnutrition becomes a side-effect.
Near Mervat's tent, 15-month old baby Juma Kheir's dirt-streaked face contorted in pain from a hernia causing his testicles to swell. His father Mohammed said doctors told him the hernia wasn't an urgent medical case, and so aid agencies couldn't cover the cost of treating it. Meanwhile, Juma can't eat and his mother feared he was wasting away. His twin was noticeably chubbier and heavier.
Mervat said her other children were often hungry because they had no money to buy food and relied on U.N. donations.
"I'm worried about them, I'm afraid of the future," said Mervat.