Reiki practitioners believe that therapeutic effects of this technique are obtained from a "universal life energy" that provides strength, harmony, and balance to the body and mind. Life energy is thought to be transferred to patients when practitioners place their hands on or directly above treatment areas. This life energy is thought to vitalize organs and cells and to release trapped negative energy. Practitioners do not view themselves as the sources of life energy.
Reiki practitioners believe that human energy flows through meridians (or pathways) in the body that can be sensed by trained individuals. A disturbance in the flow of this energy may be caused by physical illnesses or negative emotions. Reiki practitioners aim to channel life energy to problem areas where the patient's energy flow is sensed as being disrupted.
Practitioners believe that Reiki can treat symptoms and enable patients to feel enlightened with improved mental clarity, well-being, and spirituality. Reiki is sometimes administered to patients who are dying with the goal of instilling a sense of peace.
It has been proposed that Reiki can lower heart rate and blood pressure, boost the immune system and endocrine (hormonal) systems, stimulate endorphins, or affect skin temperature and blood hemoglobin levels. However, these properties have not been well-studied or clearly demonstrated in scientific studies.
Reiki has been used or suggested for the management of many conditions. However, Reiki is not well studied scientifically. There are several challenges to conducting high quality research on techniques such as Reiki: there are different styles of practice with variation from practitioner to practitioner; it is challenging to design studies with "placebo" Reiki; and there is no widespread agreement on how best to measure outcomes. Better research is needed before a recommendation can be made either for or against the effectiveness of Reiki for any specific condition.
Autonomic nervous system disturbances:
One randomized trial suggested that Reiki may have an effect on autonomic nervous system functions such as heart rate, blood pressure, or breathing activity. Large, well-designed studies are needed before conclusions can be drawn.
Reiki may contribute to reduced perception of pain, improved quality of life, and reduced fatigue in cancer patients. More studies are needed.
Cognitive disorders (mild cognitive impairment):
Early research suggests that Reiki therapy may improve behavioral and memory problems in patients with mild cognitive impairment or mild Alzheimer's disease. However, additional studies are needed to confirm these findings.
Depression and stress:
There is evidence that Reiki can reduce symptoms of distress when compared to placebo. More information is needed before a conclusion can be drawn.
Reiki instruction may help HIV/AIDS patients reduce pain or anxiety, but results are unclear.
Patients in a preliminary ("phase II") trial of Reiki in combination with standard pain medications (with opioids) were reported to experience improved pain control. Further research is needed to confirm these findings.
In a randomized controlled trial, Reiki did not have any clinically useful effect on stroke recovery in patients receiving appropriate rehabilitation therapy. Selective positive effects on mood and energy were noted.