About the Research Databases

The Wellness Evidence team of doctor consultants selected four of the most respected evidence-based medicine databases that are also particularly useful for wellness-focused research: Natural Standard, The Cochrane Library, PubMed and the TRIP Database.

Please read “Important Things to Know,” including info on each database.

We’ve made researching a particular therapy simple by pre-searching the evidence at each database. (See evidence below.) However, please note that evidence-based medicine relies on a research hierarchy, because not all evidence is created equalLearn more about how the medical experts classify this research.

We’d like to hear from you. If there is a Wellness Evidence discipline you would like to see on these pages, please email us.

Natural Standard

An international research collaboration that systematically reviews (and limits its focus to) scientific evidence on complementary and alternative medicine (CAM). Founded in 2000, Natural Standard assigns a grade to each CAM therapy, reflecting the level of available scientific data for or against the use of each therapy for a specific medical condition.

Natural Standard is subscription-based, and each of the database’s monographs aggregates data from other resources like AMED, CANCERLIT, CINAHL, CISCOM, the Cochrane Library, EMBASE, HerbMed, International Pharmaceutical Abstracts, Medline and NAPRALERT – and 20 additional journals. Data analysis is performed by healthcare professionals conducting clinical work and/or research at academic centers, using standardized instruments pertaining to each monograph section


Biofeedback is a purported technique for helping an individual become conscious of otherwise unconscious body processes. Through conveying information about blood pressure, heart rate, skin temperature, galvanic skin response (sweating), and muscle tension in real-time, biofeedback aims to raise awareness and conscious control of the related physiological (natural biological processes) activities. In essence, biofeedback attempts to use the mind to control the body.

Neal Miller, a psychologist and neuroscientist who worked and studied at Yale University, is generally considered to be the father of modern-day biofeedback. In the 1950s, he came across the basic principles of biofeedback when doing animal experimentation conditioning the behavior of rats. His team found that by stimulating the pleasure centers of the rats’ brains with electricity, it was possible to train rats to control phenomena ranging from their heart rates to their brainwaves. Until that point, it was believed that bodily processes like heart rate were under the control of the autonomic nervous system and not responsive to conscious effort.

Biofeedback has been shown to be helpful in treating a variety of medical conditions including asthma, Raynaud’s disease, irritable bowel syndrome, hot flashes, nausea and vomiting associated with chemotherapy, incontinence, headaches, irregular heartbeats (cardiac arrhythmias), high blood pressure, and epilepsy. Other common uses may include the treatment of stress and stress-related conditions such as anxiety and insomnia.

Interest in biofeedback has fluctuated since its development in the 1960s. Today, it is becoming popular once more, possibly because of the general increase of interest in complementary and alternative medicine modalities.


Biofeedback training may be performed in physical therapy clinics, medical centers and hospitals. A typical biofeedback session lasts 30 to 60 minutes. The cost varies depending on whether a person’s insurance covers all or part of the procedure. Different doctors or health institutions may charge varying amounts.

During a biofeedback session, a therapist applies electrical sensors to different parts of a patient’s body. These sensors will monitor the physiological response to stress, for example, muscle contraction during a tension headache, and then feed the information back to a person via auditory (hearing) and visual (seeing) cues. These cues may be in the form of a beeping sound or a flashing light. With this feedback, a person may begin to associate the body’s response with certain physical functions, such as muscles tensing.

The next step is to learn how to invoke positive physical changes in the body, such as relaxing specific muscles when the body is physically or mentally stressed. The goal of biofeedback is to eventually be able to produce these responses alone, outside of the therapist’s office and without the help of technology.

Several techniques may be used to gather information about an individual’s bodily responses. The one used may depend on individual health conditions and objectives, and is determined by a biofeedback practitioner. Machines and techniques may include:

Electroencephalogram (EEG): An EEG monitors the activity of brain waves linked to different mental states such as wakefulness, relaxation, calmness, light sleep and deep sleep. This process is also known as neurofeedback.

Electromyogram (EMG): An EMG uses electrodes or other types of sensors to measure muscle tension. The EMG makes a patient aware of muscle tension allowing him/her to recognize the feeling early on and try to control the tension right away. EMG may be used to promote the relaxation of those muscles involved in backaches, headaches, neck pain and grinding teeth (bruxism). An EMG may be used to treat some illnesses in which the symptoms tend to worsen under stress, such as asthma and ulcers.

Galvanic skin response training: Sensors measure the activity of a person’s sweat glands and the amount of perspiration on the skin, indicating the presence of anxiety. This information can be useful in treating emotional disorders such as phobias, anxiety and stuttering.

Temperature biofeedback: Sensors attached to fingers or feet measure skin temperature. Because body temperature often drops when under stress, a low reading can prompt a person to begin relaxation techniques. Temperature biofeedback may help treat certain circulatory disorders, such as Raynaud’s disease, or reduce the frequency of migraines.


Biofeedback is based on the concept that the mind can control the body. Using visual and auditory feedback from a variety of monitoring procedures and equipment, a biofeedback specialist aims to teach a person to control certain involuntary body responses such as brain activity, blood pressure, muscle tension, and heart rate. Once able to recognize and control these responses, individuals may be able to manage a wide range of mental and physical health problems.

There are hundreds of studies published using biofeedback for a variety of conditions including malnutrition, stress, complex regional pain syndrome, bladder disorders, heart problems, and hypertension.

Biofeedback may help reduce or even eliminate the need for medication in certain conditions, and possibly improve conditions that have not responded to other types of therapy. It is thought to help put a person in charge of his/her own healing by providing measurable feedback and monitoring progress and learning. Furthermore, using biofeedback may decrease medical costs.

Neurofeedback, using an EEG, has become a popular treatment for Attention Deficit Hyperactivity Disorder (ADHD), and electromyogram (muscle tension) biofeedback has been widely studied and accepted as a treatment for incontinence disorders (inability to control the urinary bladder or bowels). Small home biofeedback machines are becoming available for a variety of uses.

Based on several studies, biofeedback may be superior to laxatives in the treatment of constipation. It has also been reported that preoperative behavioral training may hasten the recovery of urine control and decrease the severity of incontinence following radical prostatectomy (surgical removal of the prostate).

A review of several studies found that biofeedback-based behavioral treatments reduce blood pressure (BP) to a modest degree. Effect sizes were quite variable. According to the authors, thermal feedback and electrodermal activity feedback may be superior to EMG or direct BP feedback, which tend to produce null effects.

Pelvic floor rehabilitation, a form of biofeedback, may be an appealing treatment for patients with fecal incontinence. A study assessed the outcome of pelvic floor rehabilitation in a large series of consecutive patients with fecal incontinence due to different causes. Pelvic floor rehabilitation led to a modest improvement in severity of fecal incontinence, squeeze pressure and maximal tolerated volume. In a few patients, a substantial improvement of the baseline Vaizey incontinence score was observed. Further studies are needed to identify patients who are most likely to benefit from pelvic floor rehabilitation.

The results of one study conclude that biofeedback is equally effective compared to alpha-antagonists in the treatment of recalcitrant voiding dysfunction.

Habit cough is a persistent ‘barking’ cough that does not have a determined medical cause. A study evaluated a biofeedback approach using skin temperature feedback with a family focus in the treatment of an 11 year-old girl diagnosed with habit cough. Treatment consisted of six one-hour sessions involving skin-temperature biofeedback to teach relaxation during coughing episodes. The girl was cough-free at the end of the sixth session and remained cough-free at the end of one and two year follow-up observations. It is noteworthy that the girl demonstrated a significant ability to increase skin temperature when asked to control her cough.

Despite promising studies for a variety of conditions, critics argue that there is no consistent evidence to suggest that autogenic training is superior to other interventions for prevention of tension headaches. Further studies should investigate the use of standard autogenic training in patients with moderate headache.


Although biofeedback is generally considered safe, consult with a qualified healthcare professional before making decisions about new therapies and/or related health conditions.

Biofeedback may interfere with the use of some medications, such as insulin.

Behavioral modification therapies should not delay the time to diagnosis or treatment with more proven techniques or therapies, and should not be used as the sole approach to illnesses.

cticed by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.

Author Information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Abgrall-Barbry G, Consoli SM. Psychological approaches in hypertension management. Presse Med. 2006 Jun;35(6 Pt 2):1088-94. View Abstract
  2. Association for Applied Psychophysiology and Biofeedback (AAPB). Biofeedback. 9, June 2006. www.aapb.org
  3. Bruehl S, Chung OY. Psychological and behavioral aspects of complex regional pain syndrome management. Clin J Pain. 2006 Jun;22(5):430-7. View Abstract
  4. Burgio KL, Goode PS, Urban DA, et al. Preoperative biofeedback assisted behavioral training to decrease post-prostatectomy incontinence: a randomized, controlled trial. J Urol. 2006 Jan;175(1):196-201; discussion 201. View Abstract
  5. Chiari L, Dozza M, Cappello A, et al. Audio-biofeedback for balance improvement: an accelerometry-based system. IEEE Trans Biomed Eng. 2005 Dec;52(12):2108-11. View Abstract
  6. Chiarioni G, Whitehead WE, Pezza V, et al. Biofeedback is superior to laxatives for normal transit constipation due to pelvic floor dyssynergia. Gastroenterology. 2006 Mar;130(3):657-64. View Abstract
  7. Ernst E. Complementary/alternative medicine for hypertension: a mini-review. Wien Med Wochenschr. 2005 Sep;155(17-18):386-91. View Abstract
  8. George R, Chung TD, Vedam SS, et al. Audio-visual biofeedback for respiratory-gated radiotherapy: Impact of audio instruction and audio-visual biofeedback on respiratory-gated radiotherapy. Int J Radiat Oncol Biol Phys. 2006 Jul 1;65(3):924-33. View Abstract
  9. Husmann DA. Use of sympathetic alpha antagonists in the management of pediatric urologic disorders. Curr Opin Urol. 2006 Jul;16(4):277-82. View Abstract
  10. Kanji N, White AR, Ernst E. Autogenic training for tension type headaches: A systematic review of controlled trials. Complement Ther Med. 2006 Jun;14(2):144-50. Epub 2006 May 18. View Abstract
  11. Labbe EE. Biofeedback and Cognitive Coping in the Treatment of Pediatric Habit Cough. Appl Psychophysiol Biofeedback. Epub 2006 May 23. View Abstract
  12. Linden W, Moseley JV. The efficacy of behavioral treatments for hypertension. Appl Psychophysiol Biofeedback. 2006 Mar;31(1):51-63. View Abstract
  13. Place N, Martin A, Ballay Y, et al. Neuromuscular fatigue differs with biofeedback type when performing a submaximal contraction. J Electromyogr Kinesiol. Epub 2006 Jun 1. View Abstract
  14. Terra MP, Dobben AC, Berghmans B, et al. Electrical Stimulation and Pelvic Floor Muscle Training With Biofeedback in Patients With Fecal Incontinence: A Cohort Study of 281 Patients. Dis Colon Rectum. Epub 2006 Jun 15. View Abstract


British epidemiologist Archie Cochrane is regarded as the originator of the Evidence-Based Medicine concept (in the 1950s). And the Cochrane Library is a collection of very high-quality medical databases, which have, at their core, the Cochrane Reviews, systematic reviews and meta-analyses which summarize and interpret the results of well-conducted, randomized controlled trials… the ‘gold standard’ in Evidence-Based Medicine.

The Cochrane Library is a subscription-based database but offers free access to abstracts.


A service of the U.S. National Library of Medicine, PubMed was released in 1996 as a free digital archive of references and abstracts on life sciences and biomedical topics. PubMed comprises 20-million-plus citations for biomedical literature from MEDLINE, life science journals and online books from around the world. Some 11.5 million articles are listed with their abstract and 3.1 million articles are available in full-text for free.


The TRIP Database, launched in 1997, is a search engine designed to allow clinicians to quickly find answers to their medical questions using the best available evidence. Trip’s founders realized medical professionals were being forced to perform time-consuming searches at multiple websites to get at the most relevant information. So, they designed TRIP as a meta-search engine, allowing users to both simultaneously search thousands of databases, medical publications and resources, as well as easily filter the results: limiting searches to the most stringent, highest-quality medical evidence or expanding them to include results like patient information, news articles, etc.