The efficacy of acupuncture is to dredge the channel,adjust qixue,support right and dispel evil and regulate yin and yang by needling,moxibustion and other methods like cupping which work on acupoints and parts of body。Needling usually causes sour,paralysis,swelling pain and so on,and the doctor who will get particularly feeling,such as heaviness and tightness when operating(you got my words,so I gave you the answer)