Mitochondrial Dysfunction Can Appear in Many Ways.
Research has found a degree of mitochondrial dysfunction as a root cause for all of the common conditions listed below.

ADD/ADHD
Anxiety disorder
Autism spectrum disorders
Chronic fatigue syndrome
Common variable immunodeficiency (CVID)
CRPS and other chronic pain disorders
Cyclic vomiting syndrome
Depression
Dysautonomia
Epilepsy
Fibromyalgia
Irritable bowel syndrome
Migraine
POTS

All of the abovelisted conditions are complex, with multiple factors contributing in the cause of disease within each individual person. All of these conditions are related in some manner to mitochondrial dysfunction or mitochondrial disease.