For North Koreans, the definition of success is when you can eat an occasional egg, preferably with a bowl of rice, instead of the unappetising concoction of corn and weeds on which most of the population survives. Until recently, a sizeable segment of the North Korean population could afford the basic foodstuffs that are taken for granted elsewhere. Through their hard work and ingenuity, North Koreans had pulled themselves out of the famine of the 1990s that had killed 2 million people, almost 10% of the population. This wasn't prosperity by any definition of the word, but it was at least survival.

North Korea today is in the throes of what can only be described as a great leap backwards, plunged into misery by the missteps of its 68-year-old leader, Kim Jong-il. A currency revaluation late last year, designed to restore the integrity of the socialist system, wiped out the savings of anybody with more than $30 to their name, and caused the collapse of the markets where many bought their food and earned their meagre living. The North's refusal to negotiate over its nuclear programme and various provocations against South Korea, the biggest being the suspected torpedo attack that killed 46 sailors on a South Korean warship in March, has led to a sharp reduction in donations of food from South Korea and elsewhere.

An Amnesty International report on Thursday said North Koreans lack not only food, but the most basic medical care. The report described hospitals that sounded more like torture chambers with major surgery performed without anaesthesia. "Five medical assistants held my arms and legs down to keep me from moving. I was in so much pain that I screamed and eventually fainted from the pain,'' a 24-year-old man, who had his leg amputated from the calf down after falling off of a train, told Amnesty's researchers. The statistics cited in the report were equally grim: North Korea's spending on healthcare is less than $1 per capita, among the lowest in the world. At least 5% of North Koreans have tuberculosis. Forty-five per cent of children under five are stunted as a result of malnutrition.

Children and the elderly suffer from acute intestinal blockages from eating indigestible foods such as tree bark, roots and cobs. The poor diet also weakens the immune system, making people susceptible to common disease.

"In view of the enormity of the food crisis in North Korea, health issues cannot be separated from the food insecurity that has gripped the country for almost two decades,'' the report said.

Despite the perception of North Korea as the basketcase of Asia, the country once had an enviable healthcare system, with a network of nearly 45,000 family practitioners. Some 800 hospitals and 1,000 clinics were almost entirely free of charge for patients. They still are, but you don't get much at the hospital these days. The doctors, who are barely paid, expect gifts from their patients. The hospitals often have no heating, running water or electricity. You need to provide your own food, blankets, bandages, medicine.

A North Korean doctor told me that patients who needed intravenous fluid had to bring their own bottles, preferably beer bottles. "If they brought in one beer bottle, they'd get one IV. If they brought in two bottles, they would get two IV's,'' said the doctor who is now living in South Korea. "It sounds to embarrassing to admit, but that's just the way it is.''

The school system that once allowed North Korea's founder Kim Il-Sung (father of the current leader) to boast his country was the first in Asia to eliminate illiteracy has now collapsed. Students have no books, no paper, no pencils. A 17-year-old girl from Musan, a border town, who I met earlier this year in China, said many of her friends had dropped out of school because they couldn't afford the cash gifts they were expected to give their teachers.

North Koreans I've spoken with despair that their country has been thrust into reverse, the scant progress made since the famine of the 1990s now unravelling. "Things had got better for us around 2004. We were getting by. Now it's got hard again. My mother hasn't eaten white rice in two years,'' said a 28-year-old woman from Pyongsong, in the northern outskirts of Pyongyang where many of North Korea's scientific institutes are headquartered. She said people were already dying of starvation last October when she escaped from North Korea and that she'd heard conditions had deteriorated further after the currency revaluation. Her mother worked at one of the lowest level jobs in the market – as a porter, pushing one of the simple wooden carts used to transport merchandise for lack of motor vehicles. "Now she can't even do that any more."

A chatty 56-year-old woman, also from Musan, told me her family had been surviving, until the currency reform wiped them out, by buying bottles of cooking oil to divide into small plastic bags to sell since most people couldn't afford to buy more than a few grams. The woman, who left in mid-November, said her family feared another famine. "It was terrible in the 1990s. If you walked around the streets, you would see bodies lying everywhere,'' she said.

North Koreans heaped scorn on the currency reform, announced on 30 November. With less than 24 hours notice, all of the money in circulation was abolished and the markets closed. People were issued with a limited quantity of new money to buy subsidised food from state stores. The problem was that the state stores didn't have enough food. People stampeded to get what little there was to buy. Some took their own lives and there were reports of rioting. Eventually the ruling Workers' party backed down. They issued an apology, and to underscore their regret executed Pak Nam-ki, a 77-year-old party cadre who was blamed for bungling the economic policy. Although the markets have since been reopened, the episode left the regime badly damaged, economically and politically.

Kim Jong-il, who is in poor health, is trying to install his twenty-something youngest son, Kim Jong-eun, as his successor, with the hope he can take the regime established by his father into a third generation. His confidence that he can do so might be a result of the feat he pulled off after the death of his father in 1994. With North Korea's economy in freefall and the Soviet Union having collapsed, Kim not only took power, but preserved North Korea's political system, defying all predictions of the regime's collapse. If the North Korean regime manages to do it again, it will be nothing short of a miracle. "I don't think it will be like the 1990s , when people died because they didn't know any better,'' said Lee, the woman from Musan. "People are complaining now. They know the general [Kim Jong-il] is doing a bad job.."

Barbara Demick's book about North Korea, Nothing to Envy, won the 2010 Samuel Johnson prize this month