In situations of stress, there is increased activity of the sympathetic nervous system, which leads to the "fight or flight" response. Physiologic changes include increased heart rate, blood pressure, rate of breathing, blood supply to the muscles, and dilation of the pupils. It has been proposed that frequent stressful situations may lead to negative effects on health, such as high blood pressure, raised cholesterol levels, gastrointestinal distress, or depression of the immune system.
In contrast to the stress response, relaxation is characterized by reduced sympathetic nervous system tone and increased parasympathetic activity. This may include decreased metabolism, blood pressure, oxygen consumption, and heart rate, as well as a feeling of calmness. Increased brain wave slow wave activity (measured on EEG) has been reported. Alterations in the immune system may also play a role (such as changes in cytokine activity).
It has been theorized that by learning how to self-initiate the relaxation response, negative effects of chronic stress may be counter-balanced. There are some reports that states of relaxation can be achieved after several seconds with practice. Massage, deep meditative states, mind/body interactive techniques, and certain types of music and sounds have been suggested as means of establishing a state of relaxation. Rhythmic, deep, visualized, or diaphragmatic breathing may be practiced. Mental imagery, biofeedback, desensitization, cognitive restructuring, and adaptive self-statements may also be included in techniques.
Jacobson muscle relaxation or "progressive relaxation" involves flexing specific muscles, holding that position, then relaxing the muscles. This technique often involves progressing through the muscle groups of the body one at a time, beginning with the feet, spending approximately one minute on each area. Progressive relaxation may be practiced while lying down or sitting. This approach has been suggested for psychosomatic disorders, for pain relief, to ease physical tension, to relieve "inner unrest," to overcome psychosomatic disorders, and to relieve pain.
The Laura Mitchell approach involves reciprocal relaxation, moving one part of the body in the opposite direction from an area of tension, and then letting it go.
No formal credentialing or licensure exists for these relaxation techniques. Courses are offered at institutions including the National Institute for Clinical Applications of Behavioral Medicine (NICBM), the American Holistic Medical Association (AHMA), and the Center for Mind-Body Medicine (CMBM).
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Numerous human studies report that relaxation techniques (for example using audio tapes or group therapy) may moderately reduce anxiety, particularly in individuals without significant mental illness. Relaxation may be beneficial for phobias such as agoraphobia, panic disorder, work-related stress, and anxiety due to serious illnesses, prior to medical procedures, or during pregnancy. However, because there are many types of relaxation techniques used in studies, and many trials do not clearly describe design or results, a strong recommendation cannot be made without better human evidence.
Early research in patients with angina reports that relaxation may reduce anxiety, depression, frequency of angina episodes, need for medication, and physical limitations. Large well-designed studies are needed to confirm these results.
Preliminary studies of relaxation techniques in individuals with asthma report a significant decrease in asthma symptoms, anxiety, and depression, along with improvements in quality of life and measures of lung function. Further large trials in humans are needed to confirm these results.
Chemotherapy induced nausea and vomiting:
Early human trials report that relaxation techniques may be helpful in reducing nausea related to cancer chemotherapy. Better quality research is necessary before a firm conclusion can be drawn.
There is promising early evidence from human trials supporting the use of relaxation to reduce symptoms of depression,although effects appear to be short-lived. Better quality research is necessary before a firm conclusion can be drawn.
Relaxation has been reported to reduce fibromyalgia pain. However, results from other studies are conflicting, and therefore further research is needed before a clear recommendation can be made.
Preliminary evidence suggests that relaxation techniques may be helpful for the reduction of migraine headache symptoms in adults. Study of relaxation in children with headaches has yielded unclear results. Additional research is necessary before a firm conclusion can be drawn.
Heart attack risk reduction:
Early research of relaxation techniques in people who have had a heart attack suggests that fewer future heart attacks may occur when relaxation is regularly practiced. However, only a small number of patients have been studied, and better research is necessary before a firm conclusion can be reached.
Early studies suggest that progressive muscle relaxation training may benefit patients with heart failure when used as an adjunct to standard care.
High blood pressure:
Relaxation techniques have been associated with reduced pulse rate, systolic blood pressure, diastolic blood pressure, lower perception of stress, and enhanced perception of health. Further research is needed to confirm these results.
Mental health and quality-of-life improvements have been seen in preliminary studies of HIV/AIDS patients. These findings suggest the need for further, well-controlled research.
Preliminary research in patients with Huntington's disease has evaluated the effects of either multisensory stimulation or relaxation activities (control) for four weeks, with unclear results. Further research is necessary before a conclusion can be drawn.
Several human trials suggest that relaxation techniques may be beneficial in people with insomnia, although effects appear to be short-lived. Research suggests that relaxation techniques may produce improvements in some aspects of sleep such as sleep latency and time awake after sleep onset. Cognitive forms of relaxation such as meditation are reported as being slightly better than somatic forms of relaxation such as progressive muscle relaxation (PMR). However, most studies in this area are not well-designed or reported. Better research is necessary before a firm conclusion can be drawn.
Irritable bowel disease:
Early research in humans suggests that relaxation may aid in the prevention and relief of irritable bowel disease symptoms. Large, well-designed trials are needed to confirm these results.
There is promising early evidence from human trials supporting the use of relaxation techniques to reduce menopausal symptoms,although effects appear to be short-lived. Better quality research is necessary before a firm conclusion can be drawn.
Results of randomized controlled studies of relaxation techniques for obsessive-compulsive disorder show conflicting results. Further research is needed before conclusions can be drawn.
In a randomized study of patients with osteoarthritis pain, Jacobson relaxation was reported to lower the level of subjective pain over time. The study concluded that relaxation might be effective in reducing the amount of analgesic medication taken by participants. Further well-designed research is needed to confirm these results.
Most studies of relaxation for pain, including post-operative pain and low back pain, are poor quality and report conflicting results. Better research is necessary before relaxation techniques can be recommended either alone or as an addition to other treatments for acute or chronic pain.
In a randomized clinical trial, mime therapy - including automassage, relaxation exercises, inhibition of synkinesis, coordination exercises, and emotional expression exercises - was shown to be a good treatment choice for patients with sequelae of facial paralysis.
Premenstrual syndrome (PMS):
There is early evidence that progressive muscle relaxation (PMR) training may improve physical and emotional symptoms associated with PMS. Further research is necessary before a conclusion can be drawn.
Limited preliminary research reports that muscle relaxation training may improve function and well-being in patients with rheumatoid arthritis. Additional research is necessary before a conclusion can be reached.
Early research reports that relaxation with imagery may reduce relapse rates in people who successfully completed smoking cessation programs. Better study is needed in this area before a firm conclusion can be reached.
A small study showed that biofeedback assisted relaxation (BFRT) benefits patients with neurocardiogenic syncope. Further study is necessary to confirm these results.
Tinnitus (ringing in the ears):
Relaxation therapy has been associated with benefits in preliminary studies of tinnitus patients. Further research is needed to confirm these results.
Studies assessing relaxation to improve psychological well-being and "calm" in multiple types of patients have reported positive results, although the results of most trials have not been statistically significant. Although this research is suggestive, additional work is merited in this area before a firm conclusion can be drawn.
Myocardial infarction (heart attack):
Initial research in which patients were given an advice and relaxation audiotape within 24 hours of hospital admission for a heart attack found a reduction in the number of misconceptions about heart disease, but no benefits on measured health-related outcomes.
Post-traumatic stress disorder:
Relaxation has been studied for post-traumatic stress disorder with no benefit seen in these patients.