Conventional drug acts as a "rifle gun" while hydrogen as a "machine gun".

Most of the drugs used in modern medical treatments are symptomatic treatments and are far from being a cure for the diseases. The adverse effects are unavoidable in the drugs in modern medical treatments. Molecular hydrogen (H) has a remarkable therapeutic effect on various diseases, and many clinical studies have reported that H has no adverse effects. Therefore, H is a novel medical gas that is outside the concept of modern medical treatment. H, unlike drugs, works on the root of many diseases by scavenging the two kinds of strong reactive oxygen species, hydroxyl radical (·OH) and peroxynitrite (ONOO). Since the H alleviates the root of diseases and can treat many diseases at the same time, the medical application of H may be called "machine gun therapy." In this review, we demonstrated that the root of many diseases is based on ·OH-induced oxidative stress in the mitochondria, and at the same time, the root of chronic inflammation is also attributed to ·OH.