A large amount of research has been conducted to investigate how acupuncture therapy works at a physiological level. The majority of studies have focused on the effects of acupuncture therapy in relieving pain and inflammation. However there are many other physiological effects of acupuncture therapy that are identified including modifying cardiovascular functions, gastric acidity and motility, bladder pressure, as well as many other actions.
One of the most common actions of acupuncture therapy is regulating the balance between the sympathetic (fight and flight) and parasympathetic (rest and digest) nervous systems. Increasing parasympathetic activation produces relaxation, reduced heart rate and blood pressure, improved sleep patterns and enhanced digestion.
Acupuncture therapy relieves pain via a series of complex signalling pathways, mediators and receptors. When an acupuncture point is stimulated (for instance on the hand or foot) a signal travels up the spine to the brain stem and brain where a series of interactions are triggered between particular brain centers. This is known as the “mesolimbic loop of acupuncture analgesia” and involves numerous brain centers and mediators including serotonin, dopamine, noradrenaline and endogenous opioids such as endorphins. Over 30 chemical mediators have been identified as participants in this process. The completion of the mesolimbic loop then triggers another signal which is picked up by sensory neurons, producing a pain relieving effect. For those who are interested in the details of the physiology, a number of excellent review articles have been published in recent years.
Acupuncture therapy has anti-inflammatory actions which are relevant to numerous inflammatory conditions including allergic rhinitis. Dr John McDonald studied the anti-inflammatory effects of acupuncture therapy in persistent allergic rhinitis in his PhD thesis. Two review articles were published by Dr McDonald and his colleagues on this subject.