Richard Carlson, 45; self-help author

Richard Carlson, a psychologist who became a best-selling author with the reassuringly titled self-help book “Don’t Sweat the Small Stuff,” has died. He was 45.

Carlson was stricken Wednesday while en route to New York to promote his new book, “Don’t Get Scrooged,” about combating holiday stress, said Julie Mitchell, spokeswoman for HarperSanFrancisco, Carlson’s publisher.

His website, dontsweat.com, said the cause was cardiac arrest.

A self-described “happiness consultant,” Carlson advocated tackling life with good humor, positive thinking and perspective. Some critics found his approach simplistic, but his folksy advice resonated with readers: “Don’t Sweat the Small Stuff,” published in 1997, was on bestseller lists for two years.

Carlson would go on to write 20 books in all. Published in 135 countries and translated into more than 30 languages, they include “Don’t Sweat the Small Stuff in Love,” co-written with Kris Carlson, his wife of 25 years; “Don’t Sweat the Small Stuff With Your Family” and “Don’t Sweat the Small Stuff at Work.”

He tackled weightier issues -- such as death, divorce and financial crisis -- in the aptly titled “What About the Big Stuff?”

The genesis of the “Don’t Sweat” series was a conversation a decade ago with his then 4-year-old daughter. They were stuck in traffic on the San Francisco-Oakland Bay Bridge when she noticed the tense faces of the drivers around them and asked, “Why is everyone so angry?” It sparked Carlson, who was already teaching stress-reduction classes, to consider what was really worth getting upset about.

He learned to use his own advice when he was flooded with requests to promote his book.

“The first time on ‘Oprah,’ ” he told the Contra Costa Times a few years ago, “I was really nervous. And she said, ‘Don’t worry, it’s just 20 million people watching. But if you think about it, it’s no different than talking to your next-door neighbor. Just talk. Just let go of it.”

A motivational speaker and author of a syndicated column, Carlson said he tried not to let minor things rankle him, such as a bad review or being gently rear-ended while driving.

“I try to walk my talk as much as I can,” he said. “We’re here for this little tiny millisecond in eternity, and you can make of your life what you will. You can look for what’s right and what’s good and try to be kind instead of rude. If you live that way, it makes your ordinary life sort of extraordinary.”

Born and raised in the east San Francisco Bay area, Carlson earned a bachelor’s degree from Pepperdine University in Malibu and a doctorate in psychology from Sierra College in Rocklin, Calif.

Survivors include his wife and their two teenage daughters, Jasmine and Kenna; two sisters, Kathleen Carlson Mowris of Olympic Village, Calif., and Anna Carlson of La Selva Beach, Calif.; and his parents, Barbara and Don Carlson of Orinda, Calif.

A private memorial service is planned this week. The family is requesting that in lieu of flowers, memorial donations be made to local food banks, Challenge Day, Girls Inc. or Children Inc.