With no health insurance and little money, Gilberto Carrasco, a Reno, Nev., auto mechanic, didn’t see much point in getting a physical. At 50, he felt healthy and couldn’t afford treatment even if a doctor found a medical problem.

But then his girlfriend, Eren Hernandez, figured out a way to get Carrasco a free checkup. She found a family physician who was willing to barter his services. During the physical, the doctor discovered that Carrasco had prostate cancer, catching it before the disease had spread.

“We couldn’t have afforded” Carrasco’s examination, said Hernandez, who also uses bartering to get extensive medical and dental care for other family members.

With the economy in recession and many people strapped for cash, bartering of various kinds has increased. But now health care is surpassing auto repair and advertising as the service in most demand, say people who run local barter exchanges. Alan Zimmerman, a spokesman for ITEX Corporation, the largest network of barter exchanges in North America, says in the past two years the demand for health care has jumped by more than 20 percent. The company has 551 physicians and 618 dentists who participate in its 100 local barter groups.

Barter is little more than a stopgap solution for the uninsured. But with doctors, dentists, psychiatrists, chiropractors and even cosmetic surgeons offering their services, bartering is providing a temporary safety net of sorts for some workers who have lost their jobs and health coverage. And in some cases, people who have inadequate insurance are using barter to get critical services, such as dental and vision benefits.

There are two main types of bartering: direct and indirect. In the former, people engage in direct trades of goods and services without using money. In the latter, small-business owners and individuals accumulate credits, or barter dollars, by providing specific services ranging from painting a porch to putting on a dance performance. Those barter dollars can be used to buy the services of any other network member. That way, a barber with a toothache can barter for dental work, without having to find a dentist who wants a haircut.

Many of these exchanges are designed for small business owners seeking to conserve cash. Nearly 400,000 businesses participate in about 500 trade exchanges in the United States, said Ron Whitney, executive director of the International Reciprocal Trade Association, which promotes the barter industry.

In Carrasco’s case, he used barter dollars to buy the services of Quinn Pauly, a 44-year-old family physician who joined the barter network six years ago to expand his practice. Like most doctors who participate in exchanges, he accepts barter dollars only for his services, not for lab tests or hospital expenses. Pauly said he prefers being paid in cash, and now has plenty of paying patients. But he continues to participate in the trade exchange. “I wasn’t going to fire my patients who see me with barter,” he said.

Debbie Lombardi, president of Barter Business Unlimited in Bristol, Conn., said she’s fielding about 20 calls a day from members seeking medical help, compared to just occasional calls in past years. During the past six months, she said, nearly every person wanting to join her group has been looking for health care. One man recently brought his Harley Davidson to Lombardi’s office, hoping to trade it for orthodontia treatment for his daughter.

“People want to keep their standard of care up, even if they can’t afford it,” she said, adding that she has helped people get dental implants, Lasik surgery, even the services of an obstetrician to deliver twins. “In some cases, we’re their only health insurance.”

In North Carolina, one woman bartered for more than $200,000 of medical care in hopes of finding a cure for her fibromyalgia, said Maurya Lane, president of the Barter Business Exchange Inc., in Cary. At one point, Lane said, the woman gave her chiropractor a $10,000 laser, which he then used to treat her.

One of the doctor’s in Lane’s group is Ellen Gray, a psychiatrist in Chapel Hill, who like many physicians joined the local barter exchange to get more business referrals. But now, she feels she’s doing her part to expand access to therapy both for people who don’t have insurance as well as for those who don’t want their insurance companies to know they are struggling with mental-health issues. Plus, “I just like the idea that people are taking matters into their own hands,” she said.

Many doctors, including Gray, will participate only in indirect barter exchanges, which typically charge members 6 percent fees on all purchases and sales. She thinks direct barter violates medical ethics because doctor-patient relationships should focus only on healing. She said she would never want a patient who had cleaned her carpets to think he was getting substandard care because the carpets still looked dirty.

The American Medical Association has no specific policy on bartering, but supports doctors’ freedom to choose how they want to be paid, a spokesman said. The government only bars doctors from bartering for more than the cash value of their services from Medicare, the federal program for the elderly, and Medicaid, the state-federal program for the poor and disabled. Anyone who barters more than $600 in goods and services a year must pay taxes on the transactions.

Direct bartering is conducted mostly on Web sites. A dentist in Washington, D.C., used Craigslist this past winter to offer his services in exchange for tickets to President Barack Obama’s inauguration. This spring, Peter Fountain, 50, of East Norton, Pa., posted a plea on Craigslist for a surgeon to remove a cataract. “I will paint your house, refinish your antiques, anything in the general maintenance field,” he wrote. “I need to regain my vision in order to provide my employer with the skills I have.”

Fountain, who works as a maintenance superintendent at the Western Union building in Philadelphia, said no one has responded. “I figured a lot of people considered it a joke,” he said.

Last fall, Zeo Solomon helped launch a new direct-barter Web site called favorpals which has already had several successful health care exchanges. A dermatologist did a checkup in exchange for having his office cleaned; a psychiatrist saw someone a few times in exchange for help on a Web site design, and a family doctor conducted a physical in exchange for pastries from a famous New York bakery. More than 20 percent of the 10,000 people who joined the barter site were seeking or offering health care, Solomon said.

Direct barter appears to be most common in rural areas and in the South. In Cambridge, Vt., Deb Richter, a primary-care doctor, said she and her colleagues only barter with a few patients at any given time, and that what they receive in trade rarely comes close to compensating them for their work. “This is our way to make life a little nicer and increase community spirit,” said Richter, whose medical practice is the only one in a 25-mile radius. She has received vegetables, cords of wood and lots of pies in trade for medical services. She has also swapped Viagra samples for maple syrup.

Strengthening communities is the focus of another kind of exchange system, called time banking, developed in 1980 by Edgar Cahn, a law professor at the University of the District of Columbia law school. In these groups, people trade their time rather than the cash-equivalent of goods or services. With everyone’s time considered of equal value, one hour of medical care is equivalent to one hour of painting.

Dozens of time banks operate across the country, with many offering extensive health-related services, ranging from exercise classes to medical appointments to help getting to the doctor. At Hour Exchange in Portland, Maine, which has 171 medical practitioners, more than one-fourth of the 20,000 hours that were exchanged last year related to health care, said Lesley Jones, a member.

A few hospitals, meanwhile, have devised exchange programs of their own. At Woodhull Hospital in Brooklyn, N.Y., artists without health insurance earn credits toward free care if they perform or work with patients and staff. More than 400 people, including former Broadway actors, have participated in Artist Access since it began in 2005, painting murals on walls, drawing with sick children, and coaching medical residents on breaking bad news to patients.

At Franklin Memorial Hospital in Farmington, Maine, indigent patients can work off their bills by doing volunteer work. If the patients are too ill, friends or relatives can do the volunteer work for them.

Valerie Taylor, 67, tried to pay off her $13,000 bill for colon surgery a few years ago. But, because she had to retire early due to health problems, she could only pay the hospital $50 a month. She joined the hospital’s Contract for Care program, performed about 300 hours of administrative chores over the course of a year and worked off her bill.

“People do want to pay their own way, and sometimes circumstances prevent that,” she said.