Mitochondrial disease is when parts of your body called mitochondria don't work the way they're supposed to. Mitochondria are sort of like the batteries in your body's cells – they give your body energy to do all sorts of things. If your mitochondria aren't working right, your body might not have enough energy to do everything it needs to do.
Sometimes, people are sick because they don't have enough energy. With mitochondrial disease, this happens all the time because their mitochondria are always having trouble.
Mitochondrial disease is like a traffic jam but instead of cars, the traffic is energy in the form of molecules. There are different kinds of mitochondrial disease and the symptoms of the disease people experience can be different.
Some people with mitochondrial disease might have trouble moving because their muscles don't have enough energy. Others might have trouble seeing or hearing because the parts of their body that help them see or hear don't have enough energy.
Mitochondrial disease is a serious condition and it can be very hard to diagnose. There is no cure for mitochondrial disease yet but sometimes doctors can help people feel better by giving them vitamins or other treatments.