Fibromyalgia is when some people have pain all over their body and they feel very tired too. It's like they have a lot of owies everywhere, and sometimes it's hard to do normal things like running or playing. Scientists don't know exactly what causes fibromyalgia, but they think it might be because your body's "hurt alarm" is working too hard, which makes your body feel pain when it shouldn't. This can make it hard to sleep at night, and sometimes it can make people feel sad or worried too. Doctors can help by giving people medicine and teaching them ways to take care of their body, like eating healthy food and exercising in a gentle way. It's important to listen to your body and take rest when you need it, even if your friends are running around and playing.