Anxiety—a feeling of worry, fear or nervousness—is a normal part of life for children and adults. Kids may feel anxious before the first day of school; adults, before an important work meeting or big life change. And it's not always a bad thing, in fact, anxiety helps keep us alert and often subsides once the impending event is over.

While anxiety can present in a number of ways, from an uneasy feeling in the pit of your stomach to uncontrollable panic that interferes with daily activities, the latter may signal an anxiety disorder, rather than everyday stress.

"It's normal to have apprehensions before exams or worrying about new situations, but not to the point of it being paralyzing," says Yevgeniy Gelfand, MD, a psychiatrist with Trident Medical Center in Charleston, South Carolina.

In the US, anxiety disorders, like generalized anxiety disorder (GAD), phobias and social anxiety are among the most common mental health conditions, affecting 25 percent of children between the ages of 13 and 18. Because there are a few different types of disorders that can affect kids, it’s important that parents be familiar with anxiety signs. That way, you can get your children the help they need should they have an anxiety disorder.