One of the first changes you’ll notice is some breast development. It’s the hormone ‘oestrogen’ that triggers the growth of breasts and reproductive organs. The external genitals in our pubic area will also start changing too. The vulva – (outer labia, inner labia, clitoris, urethral and vaginal openings) will become darker in colour and pubic hair will start growing on our genital area.

The shape of our body will also change. We may have been able to wear boys’ jeans in the past, but our new curvier shape – smaller waistline, rounded hips and thighs – soon makes this uncomfortable.

Pubic hair growth, the growth spurt and the increased activity of oil and sweat glands will also follow. They are caused by increases in another hormone known as ‘testosterone’. The increase in oil can cause pimples, particularly on the face. Oiliness will also affect our hair, and we may find we need to wash it more often. You’ll find more details about the changes to your skin and ways to look after it in the skincare fact sheet.

Oestrogen and another hormone called progesterone lead to changes that prepare our body for the first menstrual cycle or period. Oestrogen starts the self-cleaning process of the vagina, so we may notice a white, yellowish or clear discharge. This light discharge is just the body getting ready for menstruation, and is a perfectly normal, natural and healthy process.

Hormones affect our emotions and moods. Sometimes we can feel moody and unfriendly for no particular reason; at other times we feel on top of the world. Hormones can also affect the way we think about things. This is to be expected, as our body adjusts to all the changes taking place. Remember that most of our friends will be experiencing these thoughts and feelings as they go through puberty too.