Laser therapy is a relatively new therapeutic modality. For some time, high power lasers have been used in medical treatments such as surgery and coagulation. Some beneficial effects were noticed near the treated areas which led to research into the benefits of lower powered lasers. Laser therapy at low powers has been investigated for many years and recently authorities such as the FDA have recognized the efficacy of therapeutic lasers in some applications after many years of rigorous research.

Laser radiation directed at tissue can either be reflected off the surface of the tissue or penetrate into the tissue. Whether the light reflected or penetrates depends on several factors such as wavelength, tissue surface condition, and the beam angle of incidence.