Inside every cell in your body, tiny structures called mitochondria work around the clock to keep you alive. When they fail, the consequences can touch almost every organ you have.
What exactly is mitochondrial disease?
Your mitochondria are like the power plants of your cells — they take in oxygen and nutrients from food, then convert them into usable energy. When a genetic mutation disrupts this process, your body's cells simply cannot generate enough energy to work properly. That shortage of power is what we call mitochondrial disease.
It is not one condition but a whole family of disorders. The organs that demand the most energy — your brain, muscles, and heart — tend to suffer the most when mitochondria malfunction.
The most common types
- MELAS syndrome— Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes; affects the brain and muscles severely.
- Leber hereditary optic neuropathy (LHON)— Causes sudden and often permanent vision loss, most commonly in young men.
- Leigh syndrome— A severe neurological disorder that typically appears in infancy or early childhood.
- Kearns-Sayre syndrome (KSS)— Involves the eyes, heart, and muscles; often begins before age 20.
- MERRF— Myoclonic epilepsy and ragged-red fiber disease; causes seizures and muscle weakness.
Recognising the symptoms
One of the greatest challenges with mitochondrial disease is how wildly its symptoms can vary — even among members of the same family carrying the same mutation. They can appear at birth or emerge at any point in life.
How is it inherited?
Mitochondrial diseases are genetic, meaning they stem from mutations in DNA. They can be passed down in different patterns. Most follow the standard autosomal dominant or recessive inheritance from one or both parents. However, some are inherited exclusively through the mother, because certain mitochondrial conditions live in the mitochondria's own separate DNA — and mitochondria themselves come only from the egg, not the sperm. In rare cases, mutations arise spontaneously with no family history at all.
Diagnosis: why it takes time
Because mitochondrial diseases mimic so many other conditions and affect so many different parts of the body at once, getting the right diagnosis is notoriously difficult. There is no single test that can confirm the disease. Doctors typically combine a thorough family and medical history, neurological exams, blood and urine tests, DNA testing, and sometimes a skin or muscle biopsy. Brain MRIs, heart scans, hearing tests, and eye exams may all be needed depending on the symptoms.
Treatment options
There is currently no cure for mitochondrial disease. Treatment is focused on managing symptoms, slowing progression, and preventing life-threatening complications. What works for one person may not work for another.
Living with mitochondrial disease
While the outlook varies greatly depending on which organs are affected and how severely, many people with mitochondrial disease can live full lives with the right care. Some experience occasional flare-ups; others may see faster progression. Avoiding triggers like extreme temperatures, skipping meals, poor sleep, and high stress can make a meaningful difference in day-to-day wellbeing.
If symptoms are interfering with daily life, a visit to a specialist — ideally a medical centre with dedicated expertise in mitochondrial conditions — is essential. For emergencies like seizures or breathing difficulties, seek help immediately.