On the day she arrived at the Number Three People's Hospital to seek treatment for HIV, Cai had no symptoms. But she did have a little bit of money, and that gets quick attention in the modern-day Chinese health care system: The doctors pressured her to check in and begin a regimen of expensive intravenous drugs, warning that the alternative was a swift death, she said.

When she asked for the free anti-AIDS drugs the central government has begun providing to the poor, the doctors rebuffed her, she said, until she agreed to pay for costly tests. And when she ran through her money and all she could borrow -- her 45-day hospital stay exceeding $1,400, nearly triple her annual income -- the doctors cast her out.

"The director told me to go away and wait until I had some money," Cai said.

After years of denial about the extent of AIDS in the world's most populous country, China's leaders have unleashed a well-financed campaign to stem an epidemic that by the government's reckoning afflicts 840,000 people. But these efforts are being undermined by a relentless drive for profit within the Chinese health care system, a product of the country's shift toward capitalism. Doctors at local hospitals responsible for dispensing free pharmaceuticals are exploiting those in need, padding bills with unneeded drugs and dubious services, according to medical experts, government officials and patients.

"In China today, if you don't have money, you don't dare go to the hospital," said Odilon Couzin, director of China AIDS Info, a Hong Kong-based advocacy group. "People are suffering unnecessary hospitalizations, unnecessary testing and huge medical bills. The free AIDS treatment program is being used to create profits."

The troubles vexing China's anti-AIDS efforts reflect a broader crisis assailing the health care system. In the first three decades of Communist rule, China eradicated some diseases and dramatically increased life expectancy, employing state-funded hospitals and "barefoot doctors" -- practitioners with basic training who ran rural clinics. But in the 1980s, as China began privatizing large swaths of the economy, the old system was dismantled.

From 1980 to 2004, the central government's share of total funding for health care dropped from 36 percent to 17 percent, according to a recent state study. Doctors and hospitals became responsible for living off their profit. The state continued regulating fees for basic services, but hospitals were freed to collect profit on sales of new drugs and high-technology tests.

That decision is now widely viewed as a disaster. Pharmacies have become profit centers for Chinese hospitals, the source of up to 90 percent of revenue, encouraging doctors to overprescribe drugs, Chinese experts said. More than half of all Chinese health care spending is devoted to pharmaceuticals, as compared with about 15 percent in most of the developed world, according to a recent World Bank study.

"The hospitals have had to increase their fees and boost drug sales to compensate for the loss of state support," said Cai Renhua, a former Ministry of Health official.

Fewer than one-third of the Chinese have health insurance. From 1980 to 2004, out-of-pocket expenses tripled as a proportion of total health care spending, climbing from 20 percent to 60 percent, according to a recent Ministry of Finance study.

As costs skyrocket, many poor Chinese peasants are relying on folk remedies. Infant mortality is on the rise in some rural areas. And infectious diseases such as schistosomiasis, a chronically debilitating ailment caused by parasitic worms, are regaining traction.

In July, a report released by the Beijing-based Development and Research Center, an institute that is part of China's governing State Council, concluded that the reform of the country's health care system has been "unsuccessful."

The AIDS crisis has exposed how local profit-seeking is undermining central government initiatives. Until recently, AIDS was a taboo subject, with many doctors refusing to diagnose it. Prevention work was minimal because of discomfort with discussing sex and the Communist Party's unwillingness to acknowledge an explosion in prostitution.

But in the past two years, President Hu Jintao and Premier Wen Jiabao have made high-profile visits to AIDS patients in hospitals, and educational billboards are increasingly visible. Backed by a $95 million grant from the Global Fund to Fight AIDS, Tuberculosis and Malaria, the government launched the drug program, aiming to supply 30,000 people with free anti-retrovirals by the end of the year.

About 2,000 of the 19,000 patients who have received free drugs have stopped taking them because of side effects such as low blood pressure, insomnia, and nausea, according to medical experts. In many areas, the campaign is encountering resistance from doctors who would rather prescribe expensive medicines than give away something for free.

"The reform process has made hospitals into clubs for the rich," said Zhang Ke, an AIDS specialist at Beijing Youan hospital. "If the hospital is focused on making money, why would they tell anyone about these free drugs? There's a basic conflict of interest."

The effort here in the southwestern province of Yunnan is a test of the state's resolve. Near the meeting point of Burma, Thailand and Laos, a major source of opium, Yunnan has many intravenous drug users. The sex trade has flourished here with the growth of organized tourism. Yunnan was among the first provinces opened to foreign aid groups such as the Clinton Foundation, which is dispensing free anti-retroviral drugs to children.

Until this year, Cai, who agreed to speak on condition she be identified by her last name alone lest she jeopardize her access to care, knew little about AIDS. In April, she landed in the hospital with pneumonia. On the way out, one of the doctors took her aside.

Was she a drug user? No. Had she had a lot of sex partners? No. She was 34 years old and married, the mother of two boys. She ran a stall selling clothing. She had no insurance. She had tested positive for HIV, the virus that causes AIDS.

"I collapsed," she said. "I couldn't breathe."

Her husband confessed that he had been cheating, she said. She left him, but he forced her to give up the children, she said. An aunt reluctantly took her in, though Cai was not allowed to use the bathroom or eat with the family.

On May 25, Cai went for treatment to the Number Three People's Hospital special AIDS ward. She received an X-ray and an ultrasound. The radiologists whispered that they should not touch her. "She's got that disease," she heard one doctor say.

She surrendered a $375 deposit, nearly all the money she had. They gave her a bed in a room with three other women. The toilets were filthy. Bowls of rice contained sand and worms. Trash piled up. Bed sheets went unchanged.

After a week, the hospital told her that her money was used up and demanded more. She told them she couldn't afford to stay.

"The director said, 'You have to stay because your disease is really dangerous, and if you leave you'll be dead in three months,' " Cai said.

She borrowed money from her aunt and stayed. Twenty days later, those funds were depleted. She contacted her mother in Taiwan, who wired her more money.

No one on the hospital staff mentioned the free anti-retroviral drugs, she said. She heard about them from visiting Red Cross volunteers. They were a salve for her thoughts, now centered on suicide.

"They said, 'This is not as severe as you think,' " Cai recalled. " 'It's treatable. It's not that horrible.' " They told her to press for free drugs. The director of the AIDS ward shooed them away, she said.

Two of the patients in her room were taking anti-retroviral drugs. One, a wealthy woman, was paying $500 per month. The other, a teacher, bribed a doctor for the free drugs, said Cai. "I heard her talk about it on the phone," she said.

Someone in the ward circulated a petition calling for free drugs and more information. Cai signed. They sent it to the provincial governor. They never heard back.

In early June, an official from the Ministry of Health visited the hospital from Beijing. For the first time, a room set up as a social center for AIDS patients was opened, the door frame decorated with red hearts. She and the other patients hoped to speak with the official to complain, but the ward director picked one patient to meet with the visitor. The rest were locked inside the ward, she said.

On June 23, the doctors said she could have the free drugs. They said nothing about side effects, she recalled. They sent her to the pharmacy with a prescription for a month's supply. She returned with three bottles of pills and no instructions on how to use them.

"The doctors said you have to decide how to take them for yourself," Cai said. "I was very confused." The volunteers tracked down information from the Centers for Disease Control and Prevention.

By the middle of July, Cai had exhausted her funds but still owed the hospital nearly $400. They sent her away. She moved in with another AIDS patient, a security guard who earns about $60 a month. They took an apartment near the Kunming train station, a notorious den of pickpockets. She cannot work, she said, due to side effects from the drugs, including sleeplessness and nausea. So they live on his income, scrounging for cheap, half-rotten vegetables at a local market.

In late July and again in August, she went back to the hospital to refill her prescription. They gave her another supply after she paid $18 for tests. Both times, the AIDS ward director lectured her about the need to pay her bill.

In late September, she went back for a third refill. This time, it was $60 worth of tests or no pills. She did not have it.

So, as the month drew to a close, Cai nervously inspected her plastic pill box, each day bringing her closer to the end of her supply. Each day, wondering how she would get more pills. Wondering what would happen to her body without them.

Special correspondent Eva Woo contributed to this report.