When my older daughter was 11, she began feeling sick almost constantly. Her doctor said it was stress. When I told her grandmother this, the reply was, "She's eleven. What does an eleven-year-old have to be stressed about?"
Since at that point my daughter's father and I were splitting up our marriage and my daughter was being bullied at school, I pretty much laughed in my mother-in-law's face. My daughter had plenty to be stressed about.
Stress is one of those things that's often misunderstood, especially when it comes to teens and preteens. An adult who constantly says, "Oh, I'm so stressed" might be quite skeptical if their teenage son or daughter says the same thing. But stress has nothing to do with age. There are a lot of factors that can cause stress in someone's life, from having a lot of homework to dealing with a dysfunctional family.
Because it's so often misunderstood, teens who are experiencing stress might not know how to get help, even if they need it. Stress can easily spiral into anxiety and depression, and it's best if it's dealt with before it reaches that point.
If you're a teen dealing with stress, find someone you trust to talk to. A school counselor or teacher, a parent, someone at your place of worship if you have one. Sometimes even just talking to a friend can help. If you're a parent and you think your teen might be under stress, talk to them without judging. Validate how they're feeling and let them know you'll find help for them if they need it.
Everyone goes through times in their lives where they're under stress, even teens and younger children. It's important to catch that stress before it becomes overwhelming and deal with it in healthy ways.