Your hips may seem very narrow in comparison to your broad shoulders. Your legs and arms will probably grow more than your backbone, so your legs may seem long compared to your chest or the trunk of your body. As a result, your shape will be very different from that of a little boy. Your muscles also get bigger, especially in your legs and arms, and as these muscles develop, you will get stronger. Your chest will also get bigger as muscles and some fat accumulate there.
Many boys also notice that their nipples and breasts change during puberty.
The nipples may get a little bit bigger and the rings around the nipples may get larger and darker in colour. Some boys find that their breasts well and are painful. A few boys have a lot of swelling, which makes them very worried that they are going to grow big breasts - like a woman. This is perfectly normal. The swelling and tenderness are caused by all the hormones in your body.