Puberty! It's something that is going to happen to you that you have no control over. And it'll change you, both physically and emotionally.
But what is puberty? When does it happen? What actually happens? How will it affect you?
Will it mean that you wear strange clothes, makes strange gestures with your hands and behave in a weird manner?
No, probably not, but lots of things will happen, and so it's really important that you begin to gain some understanding of what sort of changes there are likely to be.
First off, many of the physical changes are fairly obvious: some are similar for both girls and boys, some are specific to a certain gender. Secondly, these changes begin around the time you're 10-12 years old, but even that varies quite a bit. That's the point - everyone's different and what happens to you is unique to you, so don't worry if some of your classmates seem to be further ahead, or further behind, where you are in your development.
So, puberty generally starts around the ages of 10-12 and on the whole the changes you experience are complete by the time you're 18, but that varies a lot too. It's common for girls to start to go through puberty a little before boys.
In addition to the physical changes we'll look at in a moment, there are some definite emotional changes - that's adjustments in the way you feel. For example, you may feel 'up' one moment and 'down' the next; you may find yourself having arguments with friends or family without something really serious to argue about. This is quite normal, and all part of the changes that occur in puberty.
Finally, those physical changes. Here's a summary of what you're likely to experience:
Boys and Girls: more body odour, growth of pubic hair around the genitals, growth of underarm hair, voices change to a deeper tone, developing spots (acne), growth spurt.
Girls: development of breasts (that will feed babies with milk), hips widen (as the body gets ready to give birth in later life), monthly 'periods' (menstruation) begin.
Boys: penis and testes grow, shoulders broaden, growth of facial and chest hair, some boys have 'wet dreams' as their testes produce sperm, voice 'breaks' and becomes deeper.
Exactly when these changes happen is different for each boy and girl so, don't worry - what you go through, at the time you go through it, is perfectly normal. During this period of change, when you are growing into an adult, you will be going through a period of life known as adolescence. Once these changes are complete, you will have entered adulthood.
So, lots to take in - let's have a look at a few questions and see what you think, OK?