Go to CNN iReport to share your memories of the singer.
(CNN) -- Country singer Kevin Sharp, best known for his hit "Nobody Knows," has died from "complications due to cancer," his mother said. He was 43.
Sharp was diagnosed with cancer as a teenager. He was treated, and the disease did not reoccur, but he had problems later in life because of the radiation and chemotherapy he underwent, Elaine Sharp said.
She said her son died Saturday night at her home in Fair Oaks, California.
"He had a good, strong heart," she said. "He's not hurting anymore."
His website added that he died "due to ongoing complications from past stomach surgeries and digestive issues."
Sharp grew up wanting to be a singer. According to a 1998 story from Music City News, Sharp -- who grew up in a large family that included a number of foster children -- was a high school athlete and participated in a Sacramento, California, light-opera company.
It was during his senior year in high school that he was diagnosed with a rare form of bone cancer that had spread to his lungs. The ailment led to Sharp meeting producer and songwriter David Foster through the Make-a-Wish Foundation.
Foster, known for his work with such artists as Celine Dion and Michael Buble, helped support Sharp through years of chemotherapy and a determination to wean himself from painkillers after the cancer went into remission.
In the mid-'90s, after working at an amusement park to make ends meet, Sharp landed a record deal and went to No. 1 on the country charts with "Nobody Knows." He followed that hit with a handful of others, including "She's Sure Taking It Well" and "If You Love Somebody."
The early success, he said, was "like learning how to swim by somebody throwing you into the deep end of the swimming pool," he told Country Weekly in 2012.
But he didn't forget the Make-a-Wish Foundation through his own highs and lows, becoming a representative and getting a tattoo of the organization's logo on his chest.
In later years, he traveled the country as a motivational speaker, according to his website, and wrote a book called "Tragedy's Gift."
His willingness to help others kept hope alive in himself, he told Country Weekly.
"If I didn't believe what I try to express and tell others, I wouldn't be here," he said.
Singers and industry insiders expressed their condolences on Twitter.
"Sorry to hear of the passing of Kevin Sharp," wrote Mark Wills.
"My fellow country artist Kevin Sharp passed away last night and went to spend Easter with Jesus. My prayers to the family," tweeted Billy Dean.
Sharp's website asked people who want to make a donation in his memory to give to their local chapter of the Make-A-Wish Foundation.
A memorial service is being planned in Nashville. Details were not immediately available.