Parents who believe that their child is going through puberty too early shouldn't panic, said Dr. Susan Manzi of the University of Pittsburgh Medical Center.
"It's important for parents to understand what puberty is," Manzi told Robin Roberts on "Good Morning America."
"[Puberty is] a very natural transition."
Typically, girls experience early puberty between the ages of 8 and 12, and boys experience it from ages 9 to 14.
Parents need to recognize the signs of early puberty and then go seek help, Manzi said.
For girls, the signs of puberty include breast development, pubic hair, body odor, and having a period.
Boys will get enlarged testicles and penis, body hair and body odor, and their voices will deepen.
Manzi says if boys or girls are experiencing signs of early puberty, they should be evaluated by a pediatrician.
The younger they are, the more concerned parents should be.
Experts are not sure of all the causes of early puberty. Some think it's genetic or environmental.
Manzi says some have linked the early onset of puberty to better nutrition and even obesity.
It is more likely to affect girls than boys, she added.
Also, creams and lotions containing hormones should be kept away from children because some suspect that early exposure to hormones could be a factor in girls getting early puberty.
As for boys, Manzi said, "If it does occur in boys, [it is] often related to a medical condition that can be treated."