You have really grown a lot. Or maybe you are growing slowly and you are worried you will stay as you are now, too small, too fat or too thin... During the teenage years, physical changes can be very fast, so fast in fact that sometimes you donīt have enough time to get used to them, while other changes seem to take forever. These are wonderful years for some boys and girls, complicated for many others. A little guidance can help you along the way. Teenage years are full of changes, both physical and mental, that bring many doubts.