Back to last page
Complementary & Alternative Medicine
Index Of Alternative Therapies And Modalities
When deciding to begin a complementary therapy or to see a complementary practitioner, first speak with your primary health care provider.
Before engaging in any complementary medical technique, you should be aware that many of these techniques have not been evaluated in scientific studies. Often, only limited information is available about their safety and effectiveness. Each state and each discipline has its own rules about whether practitioners are required to be professionally licensed. If you plan to visit a practitioner, it is recommended that you choose one who is licensed by a recognized national organization and who abides by the organization's standards. It is always best to speak with your primary health care provider before starting any new therapeutic technique.
Yoga is an ancient system of relaxation, exercise and healing with origins in Indian philosophy. Yoga has been described as "the union of mind, body, and spirit," which addresses physical, mental, intellectual, emotional and spiritual dimensions toward an overall harmonious state of being. The philosophy of yoga is sometimes pictured as a tree with eight branches:
- Pranayama (breathing exercises)
- Asana (physical postures)
- Yama (moral behavior)
- Niyama (healthy habit)
- Dharana (concentration)
- Pratyahara (sense withdrawal)
- Dhyana (contemplation)
- Samadhi (higher consciousness)
There are several types of yoga, including hatha yoga, karma yoga, bhakti yoga and raja yoga. These types vary in the proportions of the eight branches. In the United States and Europe, hatha yoga is commonly practiced, including pranayama and asana.
Yoga is often practiced by healthy individuals with the aim to achieve relaxation, fitness and a healthy lifestyle. Yoga may be practiced alone, or with a group. Yoga classes and video tapes are available. There are no official or well-accepted licensing requirements for yoga practitioners.
It has been hypothesized that yoga may benefit health through mind-body interactions. In yoga, poses are held for varying lengths of time using gravity, leverage and tension. Breathing techniques are also used. Rapid breathing (kapalabhati) and slow breathing (nadi suddhi) may be practiced along with stretching exercises.
Yoga has been shown to reduce heart rate and blood pressure, increase lung capacity, increase the amount of time you can hold your breath, improve muscle relaxation and body composition, cause weight loss and increase overall physical endurance. Yoga may affect levels of brain or blood chemicals, including monoamines, melatonin, dopamine, stress hormones (cortisol) and GABA (gamma-aminobutyric acid). Changes in mental functions such as attention, cognition, processing of sensory information and visual perception have been described in some research studies in humans. Suggested mechanisms of action include increased parasympathetic drive, calming of stress responses, release of hormones, and brain (thalamic) activity.
Scientists have studied yoga for the following health problems:
Yoga uses controlled breathing patterns to increase breathing efficiency. More research is needed before a recommendation can be made.
Anxiety and stress (in healthy individuals)
Several studies report that yoga may reduce anxiety and stress and improve mood in healthy people who practice yoga several times per week for 30 to 60 minutes. However, most studies have not been well designed, and different yoga techniques have been used.
Anxiety disorders, obsessive-compulsive disorder, schizophrenia
Several studies in humans report benefits of yoga in the treatment of anxiety disorders, obsessive-compulsive disorder, and schizophrenia. Kundalini meditation and relaxation have been used for anxiety disorders and obsessive-compulsive disorder. Further well-designed studies are needed before a firm conclusion can be drawn.
There is promising early evidence that yoga therapy may help treat both osteoarthritis and rheumatoid arthritis. More research is needed to confirm these results.
Multiple studies in humans suggest benefits of yoga (such as breathing exercises) when used in addition to other therapies for mild-to-moderate asthma (such as prescription drugs, diet or massage). Some research demonstrates improved lung function, overall fitness and airway sensitivity and reduced need for asthma drugs, but there is also research showing no significant changes. Many of these studies are poorly designed, and because of conflicting evidence, better research is needed before a strong recommendation can be made.
Attention-deficit hyperactivity disorder (ADHD)
There is limited study in humans of yoga in the treatment of ADHD. Further research is needed before a recommendation can be made.
Carpal tunnel syndrome
Yoga therapy has been studied for carpal tunnel syndrome, but it is not clear if there are beneficial effects. Further research is needed before a recommendation can be made.
Several studies in humans report that daily yoga may improve control of blood sugar levels in people with type 2 diabetes. It is not clear if yoga is better than any other forms of exercise therapy for this purpose. More research is necessary before a recommendation can be made.
People with heart disease should consult their health care provider before starting any new exercise program.
In one low-quality trial, yoga did not show a benefit in this area
Preliminary studies in humans report that yoga may improve fatigue in adults. However, better designed studies are needed before any conclusion can be made.
Several studies in humans suggest that yoga may benefit people with heart disease. Along with positive lifestyle changes, yoga may help decrease angina (chest pain) and improve the ability to exercise and perform household physical activities. Yoga may also improve balance, coordination, and flexibility. Yoga may improve cardiovascular function and decrease risk factors for heart disease, including high blood pressure, cholesterol and blood sugar levels. It is unclear if yoga reduces the risk of heart attack or death or if yoga is better than any other form of exercise therapy or lifestyle or dietary change. Yoga may be a useful addition to standard therapies (such as prescription blood pressure or cholesterol-lowering drugs) in people at risk of heart attack. Further research is necessary before a strong recommendation can be made.
People with heart disease should consult their health care provider before starting any new exercise program.
High blood pressure (hypertension)
Several studies in humans report benefits of yoga in the treatment of high blood pressure. However, many of these studies are not well designed. It is not clear if yoga is better than other forms of exercise for blood pressure control. Additional research is needed.
Yoga practitioners sometimes recommend that patients with high blood pressure avoid certain positions, such as headstands or shoulder stands (inverted asanas), which may temporarily increase blood pressure.
Several studies in humans support the use of yoga for depression in both children and adults. Studies have compared yoga with low-dose antidepressants, electric shock therapy or no treatment. Although this preliminary research is promising, better studies are needed that examine people with clearly defined clinical depression.
Seizure disorder (epilepsy)
Several studies in humans report a reduction in the number of monthly seizures with the use of sahaja yoga, when it is used with standard antiseizure drugs. This research is preliminary, and better studies are necessary before a firm conclusion can be drawn.
Low back pain
Preliminary research in humans reports that yoga may improve chronic low back pain. However, larger, better designed studies are needed before a firm conclusion can be drawn.
Preliminary research reports that yoga may reduce the intensity and frequency of tension or migraine headaches, decreasing the need for pain-relieving drugs. However, better studies are needed before any recommendation can be made.
Preliminary research reports that yoga may benefit sleep efficiency, total sleep time, number of awakenings, and quality of sleep. Well-designed research is necessary before a firm recommendation can be made.
Irritable bowel syndrome (IBS)
Early evidence suggests that yoga may be beneficial in the management of IBS. Further research is needed to make a recommendation.
There is limited study in humans of yoga for improving memory. Most research focuses on memory in children. Better studies are needed before a recommendation can be made.
Preliminary studies in humans report that yoga may improve posture in children. However, better-designed studies are needed before any conclusion can be drawn.
Preliminary studies in humans report that yoga (mukh bhastrika) may improve human reaction time, arousal, information processing, and concentration. Further research is needed before a clear recommendation can be made.
Lung disease and function
Limited study in adults has evaluated yoga as a treatment for lung conditions such as bronchitis, fluid around the lungs (pleural effusion) or airway obstruction. Limited study in children suggests potential improvements in pulmonary function. Better designed research is necessary before any firm recommendations can be made.
There is limited study of yoga therapy in children with mental retardation. Preliminary research reports improvements in IQ and social behavior. Better studies are needed to confirm these results and to evaluate the effects of yoga in mentally retarded adults.
There is limited study in humans of yoga for improving muscle soreness. Preliminary research suggests possible benefits of implementing yoga training as a preseason regimen or supplemental activity to lessen symptoms associated with muscle soreness. Further research is needed before a recommendation can be made.
Multiple sclerosis (fatigue, cognitive function)
There is limited study of yoga therapy in patients with multiple sclerosis. Preliminary research suggests possible improvement in measures of fatigue, but no improvement of cognitive function. Further research is needed before a recommendation can be made.
Early research suggests yoga during pregnancy is safe and may improve outcomes. Additional research is needed before a clear recommendation can be made. Pregnant women who wish to practice yoga should discuss this with their obstetrician or nurse-midwife.
Weight loss, obesity
Preliminary research does not provide clear answers. Yoga in addition to healthy eating habits may reduce weight. Better studies are necessary to form conclusions about the potential benefits of yoga alone.
Slow (delayed) ejaculation
There is early evidence to support the use of yoga in the treatment of slow ejaculation in males. Larger, well-designed, and controlled trials are needed to further assess the effects of yoga for sexual health.
Preliminary research reports that yoga may be beneficial when added to standard therapies for the treatment of heroin or alcohol abuse. However, better studies are needed before any recommendation can be made.
Preliminary study suggests possible benefits of a yoga-based exercise program on people who have had a stroke and have impaired health status and reduced level of activity. Although results seem promising, further well-designed research is needed to confirm these findings.
Ringing in the ears (tinnitus)
One study reports that yoga therapy does not improve tinnitus. Although relaxation may theoretically benefit this condition, additional research is needed before a recommendation can be made.
A small study in men showed that yogic breathing may have an antioxidant effect. Larger well-designed studies are needed before conclusions can be drawn.
Quality of life
Several studies in cancer patients report enhanced quality of life, lower sleep disturbance, decreased stress symptoms and changes in cancer-related immune cells after relaxation, meditation and gentle yoga therapy. Yoga is not recommended as a sole treatment for cancer but may be helpful as an adjunct therapy.
Two fairly low-quality trials showed mixed results regarding yoga's effect on menopausal symptoms. More, higher-quality research is needed in this area.
Yoga has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially life-threatening. Consult with a health care provider before using yoga for any use.
Chronic urologic disorders (kidney, bladder)
Hand grip strength
Heart attack prevention, treatment and rehabilitation
Immune stimulant (in breast cancer patients)
Joint pain or stiffness
| Low oxygen in the blood (hypoxemia) |
Post-traumatic stress disorder (PTSD)
Scoliosis/hyperkyphosis (extreme curvature of the spine)
Seasonal affective disorder
Sensory integration disorder
Sex offender rehabilitation
Shortness of breath
Slow (delayed) ejaculation
Speech disorders (vocal cord dysfunction)
Yoga has been well tolerated in studies, with few side effects reported in healthy people. Yoga is believed to be safe during pregnancy and breast-feeding when practiced under the guidance of expert instruction (the popular Lamaze techniques are based on yogic breathing). However, yoga poses that put pressure on the uterus, such as abdominal twists, should be avoided during pregnancy.
The following have been rarely reported:
- Nerve or vertebral disc damage Caused by prolonged postures, sometimes involving the legs
- Eye damage and blurred vision, including worsening of glaucoma Caused by increased eye pressure with headstands
- Stroke or blood vessel blockage Caused by decreased blood flow to the brain or other body parts from postures
There is a case report of a woman who presented with pneumothorax (potentially dangerous air around the lung) caused by a yoga-breathing technique called Kapalabhati pranayama. There is another report of a teen-age girl who died of obstructed breathing associated with mouth-to-mouth yoga (in which one person breathes into another person's mouth using yoga breathing techniques). However, a long-acting barbiturate (which can cause decreased breathing) may have been partially at fault. Chronic cheilitis (inflammation of the lips) and persistent reflux have been reported in yoga instructors with unclear relationship to this modality.
People with disc disease, fragile or atherosclerotic neck arteries, a risk of blood clots, extremely high or low blood pressure, glaucoma, retinal detachment, ear problems, severe osteoporosis or cervical spondylitis should avoid some yoga poses. Certain yoga breathing techniques should be avoided in people with heart or lung disease.
Some experts advise caution in people with a history of psychotic disorders (such as schizophrenia), because there is a risk of worsening symptoms, although this has not been clearly shown in studies.
You should speak with your health care provider before starting yoga or any new exercise regimen.
Yoga has been suggested for many conditions. There is preliminary evidence that yoga may be beneficial when it is added to standard treatments for several conditions, including anxiety disorders or stress, asthma, high blood pressure, heart disease and depression. It is not clear if yoga is any more or less effective than other forms of exercise. Damage to nerves or discs in the back have been reported, and caution is warranted in some individuals. Speak with your health care provider if you are considering starting yoga, or any new exercise program.
The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.
- Natural Standard: An organization that produces scientifically based reviews of complementary and alternative medicine (CAM) topics
- National Center for Complementary and Alternative Medicine (NCCAM): A division of the U.S. Department of Health & Human Services dedicated to research
Selected Scientific Studies: Yoga
Natural Standard has reviewed all of the currently available medical literature to prepare the professional monograph from which this version was created.
Some of the more recent studies are listed below:
- Ades PA, Savage PD, Brochu M, et al. Resistance training increases total daily energy expenditure in disabled older women with coronary heart disease. J Appl Physiol 2005;Apr, 98(4):1280-1285.
- Bastille JV, Gill-Body KM. A yoga-based exercise program for people with chronic poststroke hemiparesis. Phys Ther 2004;Jan, 84(1):33-48.
- Bentler SE, Hartz AJ, Kuhn EM. Prospective observational study of treatments for unexplained chronic fatigue. J Clin Psychiatry 2005;May, 66(5):625-632.
- Bernardi L, Passino C, Spadacini G, et al. Reduced hypoxic ventilatory response with preserved blood oxygenation in yoga trainees and Himalayan Buddhist monks at altitude: evidence of a different adaptive strategy? Eur J Appl Physiol 2007;Mar, 99(5):511-518.
- Bhattacharya S, Pandey US, Verma NS. Improvement in oxidative status with yogic breathing in young healthy males. Indian J Physiol Pharmacol 2002;Jul, 46(3):349-354.
- Bijlani RL, Vempati RP, Yadav RK, et al. A brief but comprehensive lifestyle education program based on yoga reduces risk factors for cardiovascular disease and diabetes mellitus. J Altern Complement Med 2005;Apr, 11(2): 267-274.
- Biswas R, Paul A, Shetty KJ. A yoga teacher with persistent reflux symptoms. Int J Clin Pract 2002;Nov, 56(9):723.
- Boyle CA, Sayers SP, Jensen BE, et al. The effects of yoga training and a single bout of yoga on delayed onset muscle soreness in the lower extremity. J Strength Cond Res 2004;Nov, 18(4):723-729.
- Brown RP, Gerbarg PL. Sudarshan Kriya yogic breathing in the treatment of stress, anxiety, and depression: part I-neurophysiologic model. J Altern Complement Med 2005;Feb, 11(1):189-201.
- Carson JW, Carson KM, Porter LS, et al. Yoga for women with metastatic breast cancer: results from a pilot study. J Pain Symptom Manage 2007;Mar, 33(3):331-341.
- Cohen L, Warneke C, Fouladi RT, et al. Psychological adjustment and sleep quality in a randomized trial of the effects of a Tibetan yoga intervention in patients with lymphoma. Cancer 2004;May, 15(10):2253-2260.
- Cohen BE, Kanaya AM, Macer JL, et al. Feasibility and acceptability of restorative yoga for treatment of hot flushes: a pilot trial. Maturitas 2007;Feb 20, 56(2):198-204.
- Dahiya S, Arora C. Impact of exercise on nutritional status and health profile of urban obese women in Hisar City. Asia Pac J Clin Nutr 2004;13(Suppl):S138.
- Galantino ML, Bzdewka TM, Eissler-Russo JL, et al. The impact of modified Hatha yoga on chronic low back pain: a pilot study. Altern Ther Health Med 2004;Mar-Apr, 10(2):56-59.
- Gerritsen AA, de Krom MC, Struijs MA, et al. Conservative treatment options for carpal tunnel syndrome: a systematic review of randomised controlled trials. J Neurol 2002;Mar, 249(3):272-280.
- Greendale GA, McDivit A, Carpenter A, et al. Yoga for women with hyperkyphosis: results of a pilot study. Am J Public Health 2002;Oct, 92(10):1611-1614.
- Jensen PS, Kenny DT. The effects of yoga on the attention and behavior of boys with attention-deficit/hyperactivity disorder (ADHD). J Atten Disord 2004;May, 7(4):205-216.
- John PJ, Sharma N, Sharma CM, et al. Effectiveness of yoga therapy in the treatment of migraine without aura: a randomized controlled trial. Headache 2007; May, 47(5):654-661.
- Johnson DB, Tierney MJ, Sadighi PJ. Kapalabhati pranayama: breath of fire or cause of pneumothorax? A case report. Chest 2004;May, 125(5):1951-1952.
- Khalsa SB. Treatment of chronic insomnia with yoga: a preliminary study with sleep-wake diaries. Appl Psychophysiol Biofeedback 2004;Dec, 29(4):269-278.
- Kuttner L, Chambers CT, Hardial J, et al. A randomized trial of yoga for adolescents with irritable bowel syndrome. Pain Res Manag 2006;Winter, 11(4):217-223.
- Madanmohan, Udupa K, Bhavanani AB, et al. Modulation of cardiovascular response to exercise by yoga training. Indian J Physiol Pharmacol 2004;Oct, 48(4):461-465.
- Manjunath NK, Telles S. Spatial and verbal memory test scores following yoga and fine arts camps for school children. Indian J Physiol Pharmacol 2004;Jul, 48(3):353-356.
- Narendran S, Nagarathna R, Narendran V, et al. Efficacy of yoga on pregnancy outcome. J Altern Complement Med 2005;Apr, 11(2):237-244.
- Oken BS, Kishiyama S, Zajdel D, et al. Randomized controlled trial of yoga and exercise in multiple sclerosis. Neurology 2004;Jun, 8(11):2058-2064.
- Sabina AB, Williams AL, Wall HK, et al. Yoga intervention for adults with mild-to-moderate asthma: a pilot study. Ann Allergy Asthma Immunol 2005;May, 94(5):543-548.
- Sareen S, Kumari V, Gajebasia KS, et al. Yoga: a tool for improving the quality of life in chronic pancreatitis. World J Gastroenterol 2007;Jan 21, 13(3):391-397.
- Shannahoff-Khalsa DS. Patients perspectives: Kundalini yoga meditation techniques for psycho-oncology and as potential therapies for cancer. Integr Cancer Ther 2005;Mar, 4(1):87-100.
- Shannahoff-Khalsa DS, Sramek BB, Kennel MB. Hemodynamic observations on a yogic breathing technique claimed to help eliminate and prevent heart attacks: a pilot study. J Altern Complement Med 2004;Oct, 10(5):757-766.
- Taneja I, Deepak KK, Poojary G, et al. Yogic versus conventional treatment in diarrhea-predominant irritable bowel syndrome: a randomized control study. Appl Psychophysiol Biofeedback 2004;Mar, 29(1):19-33.
- Visweswaraiah NK, Telles S. Randomized trial of yoga as a complementary therapy for pulmonary tuberculosis. Respirology 2004;Mar, 9(1):96-101.
- Williams KA, Petronis J, Smith D, et al. Effect of Iyengar yoga therapy for chronic low back pain. Pain 2005;May, 115(1-2):107-117.
- Woolery A, Myers H, Sternlieb B. A yoga intervention for young adults with elevated symptoms of depression. Altern Ther Health Med 2004;May-Apr, 10(2):60-63.
Last updated April 29, 2008
exercise,chronic,heart,cancer,health care,asthma,blood pressure,depression,high blood pressure,pregnancy,anxiety disorders,back pain,fatigue,lung,muscle,anxiety,brain,cardiovascular,carpal tunnel syndrome,cognitive,ejaculation,heart attack