Stress can age you. A cardiologist explains 4 simple ways to protect your heart in 10 minutes a day.

• A cardiologist said most of us have too much stress, an underrated risk factor for heart health.
• Heart disease is on the rise on young patients. Managing stress is key in your 20s, 30s, and beyond.
• A few minutes of meditation, movement, or social connection each day helps protect your heart.

In over a decade as a cardiologist, Dr. Tara Narula has seen a major risk factor for heart disease in 90% of her patients. It's completely preventable — but we're not talking about it enough.

"My patients are walking around with this level of chronic stress that is unimaginable," she told Business Insider. "And most of my patients don't know how damaging it can be."

Chronic stress can be a silent killer, putting strain on your heart that can prompt serious or even life-threatening conditions like a heart attack or stroke. These risks are on the rise in younger people, with heart disease increasingly being diagnosed among patients in their 30s or even younger.

A recent report from the American Heart Association found that women between the ages of 20 and 44 are likely to see the biggest increase in risk of heart attack, stroke, and cardiovascular disease in the next few decades.

"This is a disease that cuts across every age, and in many ways it can be silent until it's not," said Narula, chief medical correspondent for ABC News and cardiologist at Northwell Health. "Prevention is key, and that means you have to start in your 20s thinking about heart health."

Her new book, "The Healing Power of Resilience," focuses on steps we can take to reduce stress and the crucial connection between physical and mental health.

She said a few simple strategies can help reduce stress in a few minutes each day, adding up to major benefits for long-term health.

"We are not going to be able to tackle someone's heart health or their risk factors unless we address stress," Narula said.

Have an exercise snack

About 80% of the risk of heart disease can be prevented with lifestyle changes, Narula said, and stress can make it harder to keep up healthy habits.

"If you're under stress, you may not exercise, you may drink more alcohol, you may smoke, you may eat more unhealthy. So it's driving up a lot of those risk factors, but also having direct effects on the cardiovascular system," she said.

To break the cycle, start small, Narula said.

You don't need to hit the gym for an hour a day to see the benefits. She recommends adding a few minutes of activity at a time.

Sometimes called "exercise snacks," these small doses of movement can relieve stress and strengthen your heart at the same time, studies suggest. As few as 500 extra steps a day can boost longevity.

"I'm taking the stairs. I'm parking a little farther away. I'm taking a walk on my lunch break. All of those micro-movements add up over time," Narula said.

Take a meditation break

Another habit Narula swears by is a regular mindfulness practice. Setting aside a few minutes during the day to breathe deeply and calm your thoughts can quickly change your mood.

"You can sit at your desk in the middle of your office workday and do a meditation for 10 minutes that is going to get your mind in a different space than it was before," she said.

Mini-meditations or breathing exercises can be particularly helpful when used to replace stressful habits, such as doom-scrolling.

"You want to be invested and involved, but at some point, you don't want to be inundated with stuff that's making you feel bad. I think dialing off things that you know upset you is a good thing," Narula said.

Phone a friend

One of the biggest ways to boost longevity is a strong social life. Narula said reaching out to loved ones for support is a great way to ease stress. If you have a packed schedule and tend to postpone social calls, making time for even a quick message can help.

"So many of us have people that, gosh, I've been meaning to call this person in my life, and I'm so busy, I haven't done it," she said. "We put off a lot of the social stuff that we could easily find 10 minutes in the day to connect with another human being."

As you build on your support network, she also recommends finding a qualified therapist. While it takes a bit more time and effort to get started, therapy can help you work through larger issues or stress patterns in your life. Narula said it's been crucial in helping her tackle her fears about the future and let go of past events.

When it comes to heart health and overall wellness, sometimes the biggest benefits come from facing the things you struggle with the most.

"It's an investment," she said. "The more you invest in it, the bigger the payoff is going to be."