J.D. Gibbs, president of Joe Gibbs Racing and son of team owner Joe Gibbs, is undergoing treatment for "symptoms impacting areas of brain function," the racing team announced Wednesday.
Gibbs, 46, has experienced problems with "speech and processing" and has undergone tests, the team said.
Doctors believe the complications were triggered by head injuries suffered earlier in life. Gibbs played football at William & Mary in the 1980s and has long been an extreme-sports enthusiast.
As he undergoes more testing and treatment, "his presence at the race track will be limited," JGR said. He will continue to work at JGR's headquarters in Huntersville, N.C., though.
"All members of the NASCAR and France family extend our thoughts and prayers to J.D. Gibbs and his loved ones," NASCAR CEO Brian France said in a statement. "We've all watched J.D. grow up within our community, and he always has represented himself, his family, the entire Joe Gibbs Racing organization and NASCAR with the utmost professionalism, enthusiasm and energy. We wish him the best during this time and eagerly anticipate his recovery."
Gibbs has been president of his father's racing team since 1997, and the team has won three Sprint Cup titles.
Joe Gibbs, a Hall of Fame coach in the NFL, started the team in 1992.