Athens-Clarke police arrived shortly before 11 p.m. to a house on Cone Drive, responding to a report of a child not breathing, according to police.
EMTs tried to resuscitate the boy and transported him to the hospital.
The boy's aunt, who was caring for him, told police that the boy refused to eat about 8:30 p.m. and had complained of a headache.
He went to sleep, and when his aunt tried to wake him to put him to bed, she found him unresponsive and not breathing.
The boy's body was sent to the Georgia Bureau of Investigation's Crime Lab for autopsy, a standard procedure when a child dies. The autopsy showed no obvious signs of what killed the boy, and lab tests could take weeks.
But authorities don't suspect he was abused or mistreated, according to Clarke County Coroner Sonny Wilson.
"It's natural causes. Nothing appears to be suspicious," Wilson said.