When Marlene Chertok was diagnosed with breast cancer in 2002, there was nothing funny about it. She started medical treatments and also investigated some complementary healing practices. One evening, she saw a documentary about Laughter Yoga, which combines the breathing and stretching of yoga with stress-reducing laughter.

The idea appealed to her, and after her treatments ended, Chertok trained with the founder of the program, Dr. Madan Kataria of Mumbai, India. “This stuff is really powerful,” says Chertok, 58. She pauses for a hearty laugh. “I started doing Laughter Yoga for my own health and healing. Now this is my little effort to help make the world a better place.”

Chertok leads non-denominational Laughter Yoga sessions at 4 p.m. every Sunday at Eliot Unitarian Chapel in Kirkwood. Residents at Crown Center for Senior Living in University City meet with Chertok once or twice a month for sessions. Chertok also leads Laughter Yoga groups for agencies — she will be at the Wellness Community Thursday, Sept. 10 — and at private events.

Chertok took time recently to talk a bit about her unusual calling, which she refers to as building “a caring laughter community.”

What drew you originally to Laughter Yoga?

It was an experiment for me, another way to work on healing after cancer. I give talks about my healing story, called “Laugh for the Health of It,” and in that talk I encourage people to get involved with their own healing. Learning to tap the positive emotions and the healing impact they have on the body is an important tool. Learning to laugh for no reason, as we do in Laughter Yoga, gave me a tool to pull myself out of a negative state. Now, I use it for prevention.

How did you get started leading Laughter Yoga at Crown Center?

Some women who live there came to Laughter Yoga Club at Eliot Chapter, and they asked me to start a group at Crown Center. There are many ethnicities at Crown, and laughter breaks down barriers. This is Tikkum Olam, a way of repairing the world. I have enjoyed watching the group there grow, and I hope eventually to open the sessions to all residents of University City.

What has been the response?

When the people come in, some of their faces look sad, or tightly drawn. As we go through the laughter exercises, I watch them become like children — many of them leave giggling. They love it and I love them.

Tell your best story from Crown.

Last month, an 88-year-old woman entered our room, looking for a meeting that had been canceled. I invited her to stay. She said she was having pain in her face from shingles, and she was not sure she could do the exercises, but she would try. About 10 minutes into the session, the woman called out to me that her face was relaxing, that she could open her mouth wide and smile again. That is why I do this.

You say that Laughter Yoga is gaining in popularity in Israel. Why is that?

Yes – it’s really taking off in Israel. Sometimes, sessions are even aired on television there. Living conditions in Israel can be stressful, and people find Laughter Yoga helps them manage depression and stress. This is not a surprise. Laughter is indigenous to Jewish culture. It is how we survived.

(Call 314-965-0656 for information on future sessions.)

Marlene Chertok, B.S.N.

WORK: A registered nurse, Chertok works as a care coordinator for BJC Home Care.

HOME: Glendale

FAMILY: She is married to David Behrens, a biomedical technician. They have a son, Paul, who is a pharmacist, and a daughter, Tanya, a student at the University of Missouri at Columbia

HOBBIES: Chertok likes to cook, especially Middle Eastern and Indian dishes, and she enjoys walking, biking, Qi Gong and reading.

Personal accomplishment: Chertok started the St. Louis Laughter Yoga Club in 2004, one of more than 5,000 clubs in 60 countries on five continents. In 2008, she was honored with the International Laughter Yoga Ambassador Award.