Mitochondrial diseases are a group of disorders caused by dysfunction in the mitochondria, the energy-producing structures within cells. These diseases can affect various organs and systems, leading to symptoms such as muscle weakness, neurological issues, and problems with growth and development. Mitochondria are essential for converting food into energy, so when they fail, the body struggles to function properly. These diseases can be inherited from parents or occur spontaneously due to mutations in mitochondrial DNA or nuclear DNA. Diagnosis often involves genetic testing and may require a multidisciplinary approach for management. Treatments focus on alleviating symptoms and improving quality of life, as there is currently no cure for most mitochondrial diseases.