Prince Bhojwani never thought of himself as a negative person, until three trips to the hospital in one month forced him to reconsider.

Before May 2018, he was a healthy but chronically worried start-up founder who regularly did 20-mile (32-kilometer) bike rides. When he suddenly became barely able to walk, with blurry vision and spiking blood pressure, emergency room doctors suspected a stroke, but couldn't pinpoint the cause of his illness.

A close friend, however - "one of the most optimistic people I know," he said - pointed out Bhojwani often lacked faith that things would work out, and suggested that had pushed him to burn out.

"I started looking at the world very differently, literally the next day," said Bhojwani, who lives in New York City. He started meditating and taking a moment every morning to feel grateful to be alive. He also found purpose by co-founding a nonprofit, Asana Voices, a South Asian advocacy organization.

In the years since, he hasn't had any similar health crises, despite working longer hours. He credits his newfound positive outlook.

"After there was a life-changing event, it kind of forced me to become optimistic," he said. "I can't even imagine living life the way I did back then."

Optimism in itself is hardly a cure-all, but numerous studies over the decades have demonstrated a link between a positive outlook and good health outcomes.

Experts say a standard for measuring someone's relative optimism has long been the 10-question Life Orientation Test-Revised, published in 1994. (Sample question: On a scale of 1 to 5, respondents are asked how strongly they agree with the statement, "In uncertain times, I usually expect the best"?)

Generally, optimism is defined as the "expectation that good things will happen, or believing the future will be favorable because we can control important outcomes," said Hayami Koga, a postdoctoral research fellow at the Harvard Center for Population and Development Studies.

She was the lead author on a 2022 study that found optimism associated with longer life spans and a greater chance of living past 90. In another study, published in May in JAMA Psychiatry, she and other researchers said optimists generally maintained better physical functioning as they aged. They looked at 5,930 postmenopausal women over a 6-year period.

"We know that more optimistic people are more likely to live a healthier life, with healthier habits, eating healthier, having more exercise," Koga said.

Some people are born more optimistic but it can definitely be learned, too, said Sue Varma, clinical assistant professor of psychiatry at New York University and author of "Practical Optimism: The Art, Science, and Practice of Exceptional Well-Being."

Optimism training, she said, can improve life satisfaction and lessen anxiety.

"Even if you were not born with this natural disposition to anticipate favorable outcomes and see the glass as half full, there are skills that you can learn," Varma said.

Begin by noticing how you deal with uncertainty, she said. Do you tend to worry? Assume the worst?

Try to reframe the thought in an objective manner. "Is there a silver lining? Is this a problem to be solved or a truth to be accepted?" said Varma, noting that her book builds upon the work of Martin Seligman, one of the fathers of positive psychology.

Try to envision the best possible outcome and a step-by-step path to get there. Varma asks her clients to describe the path in detail until the problem is resolved, and encourages them to bask in their success.

"Then you are already approaching your day and your life as if things have worked out," she said. "And you tend to be more proactive, more positive, more resilient, more buoyant in the face of obstacles."

Finding a sense of purpose also can help. Volunteering would be beneficial, but for those who can't find the time, Varma suggested trying to remake your role at work to align better with your interests. That could be as simple as a very social person organizing outings with co-workers.

Trying to master a skill, whether a sport, a musical instrument, a language or a hobby such as knitting or chess can help prevent you from ruminating on negative possibilities.

Even with these and other interventions, it's not easy to change your mindset, Varma noted. But practice helps.

"It's a toolset, it's a mindset," she said. "I have to practice it every day in my mind.