Today, some girls begin physically maturing when they’re as young as 7 or 8 years old. That’s much earlier than girls entered puberty 10 to 30 years ago, according to a recent study published in the journal Pediatrics. The problem is that early puberty could signal a medical abnormality and affect a child’s psychological development.

Simply defined, puberty is a complex hormonal process that triggers the development of sexual characteristics. Early puberty is divided into two types: precocious or peripheral. In the most common type, precocious puberty, there are no explanations for a child’s early development and no medical reasons to stop it. But with peripheral puberty, often something more sinister, such as a cyst or tumor, may jump-start the process. In these cases, doctors step in to halt the onset.

The condition is uncommon—although it occurs more often in girls than boys—and is treatable with hormone injections or implants, says Luigi Garibaldi, MD, a professor of pediatrics at the University of Pittsburgh School of Medicine.

How much should parents worry if they notice signs of early puberty in little Susie or Mike? If the onset is abnormal, certain physical and psychological problems may arise. “Kids may experience a rapid growth spurt and end up short,” Garibaldi says. “Also, research shows girls who go through early puberty may tend to engage more in risky behavior.”

But research in this area is new and not definitive, Garibaldi warns. The best advice? Check with your pediatrician if you notice any early development.