If you get huntington's dieseas when you are a teen. What is your life expectancy? Well, I am a teen and I just want to know that if I get huntington's disease then how much longer will I live. And how well will I function in life.

Why do you ask? You're at risk for Huntington's if and only if it's affected one of your ancestors. If this applies to you, I would urge you to talk with an appropriate physician about getting tested. The age of onset and likely time of death is usually a little sooner in each generation. You need to plan your life and you need the right information.
Huntington's . Huntington's disease or chorea is an inherited disorder that usually appears in mid-life. It is referred to as autosomal dominant disorder; that is if a parent has it there is a 50/50 chance a child will inherit it. A famous person who had this movement disorder was woody guthrie, a folk singer who was born in 1912 and died in 1967. His son arlo, also a folk singer did not inherit the gene and is in his 60's ( i think). If there is a history in your family, you may wish to be tested.Some people from affected families prefer not to be tested. At this time there is no cure available. I think you would benefit from talking to your family about your worries. Good luck to you.