To many parents, text messaging is an enigma — a practice their children engage in when they could just make a phone call or walk down the street to their friends' houses. It seems to be a strange but harmless means of communication.

What most don't know is that too much texting can actually be detrimental to their teens' health. That's because new technologies, such as cell phones and social networking sites, give teenagers easy access to their friends 24 hours a day.

"The more technology we develop, the more we rely on technology," said Dr. Myrza Perez, a pediatric pulmonologist at Capital Allergy & Respiratory Disease Centers in Roseville and Folsom, Calif. A specialist in sleep disorders, she says "before technology, we went to sleep when the sun went down. Now, with all these distractions, teenagers alone in their rooms stay up to extremely late hours on their cell phones and computers. Their parents have no idea."

The trend of sleep deprivation is leading to many daytime problems for teenagers, including headaches, impaired concentration, weakened immune systems, crankiness, increased use of nicotine or caffeine and hyperactive behavior often misconstrued as attention deficit hyperactivity disorder.

These symptoms are often interpreted by doctors as problems meriting medication, when in fact the best cure might be to turn off their cell phones at night.

Mikaela Espinoza, 17, always used to sleep with her phone at her bedside, just in case a friend called or text-messaged her in the middle of the night. Sometimes, the Sacramento, Calif., teen said, she would receive calls or messages as late as 3 a.m. — and she would wake right up to call or text right back.

"Whenever I'd hear my phone ring I would just, like, wake up and answer it," Espinoza said. "I think a whole bunch of kids text like all night long."

Espinoza soon found herself suffering from near-debilitating migraine headaches throughout the day. She couldn't concentrate in school, she couldn't go out with her friends, she couldn't be herself, she said.

Her primary physician's first instinct was to check her eyes. When that yielded no solutions, he sent her in for a CAT scan. It came back clear.

"Nobody knew what was wrong with me," Espinoza said.

Eventually, Espinoza was diagnosed with a condition growing more and more common among teenagers: too much texting.

"After they realized I wasn't getting enough sleep, they told me I needed to turn off my phone or have it taken away from me at night," she said. "My mom was real mad at me."

According to the National Sleep Foundation, school-age children and adolescents need at least nine hours of sleep a night. But in a national survey conducted in 2006, only 20 percent of American teens said they get nine hours a night. Nearly half sleep less than eight hours on school nights and 28 percent of high school students reported falling asleep in school at least once a week.

The problem, experts estimate, has only worsened since then.

"We all have this 24/7 lifestyle and as technologies become more prevalent, the problem just gets worse," Perez said. "They're distractions and they lead to sleep deprivation. I feel like it's getting worse with newer technologies."

Cell phones are not the only culprits of sleep deprivation, Perez added. Video games and computers contribute to teenagers' inclination to stay up all night.

"Cell phones, computer screens and even televisions emit light rays that keep you awake," Perez said. "Light automatically stimulates the retinas. Before bed, people should turn off those devices and switch to a quieter, healthier activity, like reading."