Mitochondrial dysfunction forms the basis of human diseases like neurodegeneration, cancer, autoimmune diseases, schizophrenia, bipolar affective disorder and diabetes mellitus. Mitochondrial dysfunction can lead to apoptosis and cell death resulting in neurodegeneration. Mitochondrial dysfunction can produce increased glycolysis and the Warburg phenotype leading on to oncogenesis. The mitochondria are evolutionarily symbiotic rickettsia and the immune system recognize it as a foreign body and sets up an immune reaction leading on to autoimmune disease. All human diseases are due to mitochondrial conflict syndrome and mitochondrial dysfunction. High doses of mitochondrial supplements of vitamins like ascorbic acid, riboflavin, nicotinic acid, FMN and FAD, NAD, biotin and thiamine can be used to treat all human diseases. Linus Pauling's mega vitamin therapy can be seen as based on mitochondrial conflict syndrome and mitochondrial dysfunction as the basis of human disease.