What causes stress for a teen is a lot of different things. Most of the common ones are:
Having a Job
Not fitting in
Any extra Activities/Over Scheduled
Yet lot of the teens problems come from their homes but remember where you live could be different from another teen. Example the other teen could be living in an abusive house and you might not.
Reasons why teens get stress out.
Death of a love one (Parent, Bother, Family, Boyfriend or Girlfriend, Friend...etc...)
Change of study habits
Divorce of your own or your parents
Breakup with your boyfriend or girlfriend
Injury or Illness of your own
Trouble (fights, arguments, etc...) With parents, Girlfriend or Boyfriend, etc...
Homework and school demands
Sleeping less/Not being able to sleep
What other people think about you
Change in you habits (Start to eat less or more, begin smoking/drinking, etc..).
New work experience
Working and going to school
Outstanding or achieving something personal or in school
Staring school, Ending school, Changing to a new school
Too many activities
Not doing well in school
Problems with friends
Preparing for college
Birth of a sibling
Gaining new Responsibilities
Getting fire or being expelled or suspended from school.
Fear of failure
Living in a unsafe environment (neighborhood)
Changes in their bodies
Negative thoughts and feelings about themselves
Brothers or sisters
Things that a teen could do to alleviate their stress is to increase their physical activity. Teens should also rest and sleep the require hours of sleep. Do not stay up late you will make it difficult for your self to focus during the day. Another thing you could do is talk to someone like a good friend that you trust and most importantly relax.