Qigong and has been practiced in China for about 4000 years. Qigong improve circulation through cultivation and harnessing of Qi by practice of Qigong. Qi stagnation equal to pain and discomfort. When blood stagnate in the body cause pain and discomfort. Qi is like a hydrostatic pressure hold stem of flower keeping upright position. Better Qi flow means better health, and leads to optimal health. There are different forms of Qigong. But the difference is either more focused on physical body or spiritual body. Neither both should be excess or deficient. Both should be unite in harmony to keep balance, just like Yin & Yang symbol.
Supreme Science of Qigong - Level 3 instructor
Master Zhou's Wu Dan Qigong - Level 2 instructor