Your teen may be full of energy and may run from one activity to the next. It is easy for you to see this and assume that he or she is getting enough sleep.

But studies show that your teen is likely getting less than eight hours of sleep on school nights. He or she even may be an extreme night owl who sleeps for only five or six hours before starting another school day. This is much less than the nine hours of nightly sleep that your teen needs to feel alert and well rested during the day.

The most common sign of sleep loss is excessive daytime sleepiness. This is obvious to teachers who often see students falling asleep in class. It is harder for you to observe since you are away from your teen for most of the school day.

But there are other signs that your teen may need more sleep. Review the following list to see how many of these signs describe your teen:

• “Catching up” on sleep on weekends
• Oversleeping in the morning
• Arriving late for school
• Getting bad grades at school
• Getting into trouble at school
• Falling asleep when riding in a car or driving
• Falling asleep at home after school or in the early evening
• Falling asleep in a movie theater or while watching TV
• Lacking motivation and acting sluggish
• Drinking high-caffeine beverages to improve alertness
• Making mistakes
• Being forgetful
• Gaining weight
• Getting sick frequently
• Showing signs of depression or mood swings

Ask your teen to complete the Cleveland Adolescent Sleepiness Questionnaire. This will give you more insight into his or her level of daytime sleepiness. You also should read Teen Bed Times: Parent Tips for practical advice on how to help your teen get more sleep.

A sleep disorder such as obstructive sleep apnea (OSA) can cause teens to show signs of sleep loss. A common warning sign for OSA is loud and frequent snoring.

If you are concerned about your teen’s sleep, then talk to his or her doctor. For more help the doctor may refer you to a sleep disorders center that has been accredited by the American Academy of Sleep Medicine.