Almost every cell in the human body has mitochondria: tiny powerhouses that turn sugar and oxygen into the energy that cells need to perform their work.
In mitochondrial diseases, the mitochondria cannot turn sugar and oxygen into energy efficiently, so the body’s cells do not perform as-needed.
Mitochondrial diseases can affect one or many different parts of the body — the brain, kidneys, muscles, heart, eyes, ears, and others — in many different degrees of severity because there are many different types of mitochondrial diseases.
Not everyone with a mitochondrial disease will show symptoms. However, when discussing the group of mitochondrial diseases that tend to affect children, symptoms usually appear in the toddler and preschool years.