Increase vascular efficacy (circulation) by forming new capillaries, which are additional blood vessels that replace damaged ones. New capillaries speed up the healing process by carrying more oxygen and nutrients needed for healing, and they can also carry more waste products away.

One of the most important mechanisms of action for light therapy is the release of nitric oxide. A naturally occurring chemical in the body, nitric oxide is a key signaling molecule that can set off several beneficial effects. Most notably, it is critical in promoting blood flow to tissues. It also indirectly inhibits inflammation processes, thus reducing inflammation. In acute inflammatory responses, such as sudden injury, large increases in nitric oxide levels can play a role in increased pain. However, smaller levels of nitric oxide release, as stimulated by light therapies, can paradoxically have pain-reducing effects.

Swelling, or the natural splinting process of the body, has two basic components. The fluid which can be moved by the blood and proteins which must be moved by the lymphatic system. Research has shown that the lymph vessel diameter and the flow of the lymph system can be doubled with the use of light therapy offering a faster recovery from swelling.