Nearly one quarter of children and teens with chronic headaches are overusing over-the-counter pain relievers, according to new study findings released Thursday.

Overuse of pain relievers was defined as taking more than three doses per week for over six weeks.

Most likely children and teens are taking this medicine because they think it will relieve their headaches, and not to get any type of “high,” study author Dr. A. David Rothner of the Cleveland Clinic in Ohio told Reuters Health.

“If you have (children), and you give them medicine when they have a headache, why shouldn’t they think they can do it on their own,” he said.

There are many reasons why kids shouldn’t overuse these medicines, Rothner explained. Some pain relievers contain aspirin, which puts children under the age of 19 at risk of Reye’s syndrome, a potentially fatal disorder, he said.

Other risks of overuse of over-the-counter pain medicines include kidney failure, liver problems, and intestinal and stomach bleeding, he said.

Finally, research suggests that overusing pain relievers may cause a once-occasional headache to turn into a daily one, Rothner said.

To investigate how often kids and teens with chronic headaches take over-the-counter pain medicines, Rothner and his co-author reviewed the medical records of 680 patients ages 6 through 18 who sought help for chronic headaches. As part of a routine medical exam, children noted how many times they took pain relievers.

Around 22 percent of participants overused pain relievers, the report indicates. Overuse occurred more commonly in girls who had a chronic tension-type headache, or a mix of tension-type and migraine headaches.

Approximately one in seven kids said they took the medicines without telling their parents. Almost one in five participants said they had headaches every day, or nearly so. Most of the daily headache sufferers were girls and students who got high grades in school.

To keep kids safe from overuse of pain relievers, Rothner recommends that parents of chronic headache sufferers monitor what they take to relieve the pain.

“If you see they’re using the medicine more than twice a week, then bingo! You’ve got a problem on your hands, and you’ve got to do something about it,” he said.

The researchers presented their findings this week at the 46th Annual Scientific Meeting of the American Headache Society in Vancouver.