At least once a week, 10-30% of those under 18 years of age suffer from unexplainable headaches and abdominal pains in the United States, and the number is rising. People from collectivistic countries such as Japan, China, and Mexico are more likely to suffer from pain disorder than individualistic countries such as the US and Sweden.

Psychogenic pain, also called psychalgia, is physical pain that is caused, increased, or prolonged by mental, emotional, or behavioral factors.

Headache, back pain, or stomach pain are some of the most common types of psychogenic pain. It may occur, rarely, in persons with a mental disorder, but more commonly it accompanies or is induced by social rejection, broken heart, grief, lovesickness, or other such emotional events.

Sufferers are often stigmatized, because both medical professionals and the general public tend to think that pain from psychological source is not "real". However, specialists consider that it is no less actual or hurtful than pain from other sources.

The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, "or described in terms of such damage"" (emphasis added). In the note accompanying that definition, the following can be found about pain that happens for psychological reasons:

Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain.

Medicine refers also to psychogenic pain or psychalgia as a form of chronic pain under the name of "persistent somatoform pain disorder" or "functional pain syndrome". Causes may be linked to stress, unexpressed emotional conflicts, psychosocial problems, or various mental disorders. Some specialists believe that psychogenic chronic pain exists as a protective distraction to keep dangerous repressed emotions such as anger or rage unconscious.

It remains controversial, however, that chronic pain might arise purely from emotional causes. Treatment may include psychotherapy, antidepressants, analgesics, and other remedies that are used for chronic pain in general.

Ethnicities show differences in how they express their discomfort and on how acceptable shows of pain and its tolerance are.

Most obvious in adolescence, females suffer from this disorder more than males, and females reach out more.

More unexplainable pains occur as people get older. Typically, younger children complain of only one symptom, commonly abdominal pains or headaches. The older they get, the more varied the pain location as well as more locations and increasing frequency.

Pain is the main reason for visiting an emergency department in more than 50% of cases, and is present in 30% of family practice visits. Several epidemiological studies have reported widely varying prevalence rates for chronic pain, ranging from 12 to 80% of the population. It becomes more common as people approach death. A study of 4,703 patients found that 26% had pain in the last two years of life, increasing to 46% in the last month.

A survey of 6,636 children (0–18 years of age) found that, of the 5,424 respondents, 54% had experienced pain in the preceding three months. A quarter reported having experienced recurrent or continuous pain for three months or more, and a third of these reported frequent and intense pain. The intensity of chronic pain was higher for girls, and girls' reports of chronic pain increased markedly between ages 12 and 14.

Pain is a distressing feeling often caused by intense or damaging stimuli. Because it is a complex, subjective phenomenon, defining pain has been a challenge. The International Association for the Study of Pain's widely used definition states: "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage." In medical diagnosis, pain is regarded as a symptom of an underlying condition.

Pain motivates the individual to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease.

Pain is the most common reason for physician consultation in most developed countries. It is a major symptom in many medical conditions, and can interfere with a person's quality of life and general functioning. Simple pain medications are useful in 20% to 70% of cases. Psychological factors such as social support, hypnotic suggestion, excitement, or distraction can significantly affect pain's intensity or unpleasantness. In some arguments put forth in physician-assisted suicide or euthanasia debates, pain has been used as an argument to permit people who are terminally ill to end their lives.

There is strong evidence to show that chronic orofacial pain (including AFP) is associated with psychological factors. Sometimes stressful life events appear to precede the onset of AFP, such as bereavement or illness in a family member. Hypochondriasis, especially cancerophobia, is also often cited as being involved. Most people with AFP are "normal" people who have been under extreme stress, however other persons with AFP have neuroses or personality disorders, and a small minority have psychoses. Some have been separated from their parents as children.

Depression, anxiety and altered behavior are strongly correlated with AFP. It is argued whether this is a sole or contributing cause of AFP, or the emotional consequences of suffering with chronic, unrelieved pain. It has been suggested that over 50% of people with AFP have concomitant depression or hypochondria. Furthermore, about 80% of persons with psychogenic facial pain report other chronic pain conditions such as listed in the table.

Although in itself neither degenerative nor fatal, the chronic pain of fibromyalgia is pervasive and persistent. Most people with fibromyalgia report that their symptoms do not improve over time. An evaluation of 332 consecutive new people with fibromyalgia found that disease-related factors such as pain and psychological factors such as work status, helplessness, education, and coping ability had an independent and significant relationship to FM symptom severity and function.

Psychogenic disease (or psychogenic illness) is a name given to physical illnesses that are believed to arise from emotional or mental stressors, or from psychological or psychiatric disorders. It is most commonly applied to illnesses where a physical abnormality or other biomarker has not yet been identified. In the absence of such "biological" evidence of an underlying disease process, it is often assumed that the illness must have a psychological cause, even if the patient shows no indications of being under stress or of having a psychological or psychiatric disorder.

Examples of diseases that are believed by many to be psychogenic include psychogenic seizures, psychogenic polydipsia, psychogenic tremor and psychogenic pain.

There are problems with the assumption that all medically unexplained illness must have a psychological cause. It always remains possible that genetic, biochemical, electrophysiological or other abnormalities may be present which we do not have the technology or background to identify.

The term psychogenic disease is often used in a similar way to psychosomatic disease. However, the term "psychogenic" usually implies that psychological factors played a key causal role in the development of the illness. The term "psychosomatic" is often used in a broader way to describe illnesses with a known medical cause where psychological factors may nonetheless play a role (e.g., asthma can be exacerbated by anxiety).

Fibromyalgia is estimated to affect 2–8% of the population. Female are affected about twice as often as male based on criteria as of 2014.

Fibromyalgia may not be diagnosed in up to 75% of affected people.

Empirical studies have found that the prognosis for conversion disorder varies widely, with some cases resolving in weeks, and others enduring for years or decades. There is also evidence that there is no cure for Conversion Disorder, and that although patients may go into remission, they can relapse at any point. Furthermore, many patients who are 'cured' continue to have some degree of symptoms indefinitely.

Functional neurological disorder is a common problem, with estimates suggesting that up to a third of neurology outpatients having functional symptoms. In Scotland, around 5000 new cases of FND are diagnosed annually. Furthermore, non-epileptic seizures account for 1 in 7 referrals to neurologists after an initial seizure, and functional weakness has a similar prevalence to multiple sclerosis.

Information on the frequency of conversion disorder in the West is limited, in part due to the complexities of the diagnostic process. In neurology clinics, the reported prevalence of unexplained symptoms among new patients is very high (between 30 and 60%). However, diagnosis of conversion typically requires an additional psychiatric evaluation, and since few patients will see a psychiatrist it is unclear what proportion of the unexplained symptoms are actually due to conversion. Large scale psychiatric registers in the US and Iceland found incidence rates of 22 and 11 newly diagnosed cases per 100,000 person-years, respectively. Some estimates claim that in the general population, between 0.011% and 0.5% of the population have conversion disorder.

Historically, misdiagnosis rates have been high due to the complex nature of the disorder although some research now indicates that misdiagnosis may be reducing.

Tension myositis syndrome (TMS), also known as tension myoneural syndrome or mindbody syndrome is a name given by John E. Sarno to a condition he describes as characterized by musculoskeletal and nerve symptoms, most notably back pain. Sarno, a Professor of Clinical Rehabilitation Medicine at New York University School of Medicine and Attending Physician at The Rusk Institute of Rehabilitation Medicine at New York University Medical Center, has described TMS in four books, and has stated that the condition may be involved in other pain disorders as well. The treatment protocol for TMS includes education, writing about emotional issues, resumption of a normal lifestyle and, for some patients, support meetings and/or psychotherapy. In 2007, David Schechter (a medical doctor and former student and research assistant of Sarno's) published a peer-reviewed study of TMS treatment showing a 54% success rate for chronic back pain. In terms of statistical significance and success rate, the study outperformed similar studies of other psychological interventions for chronic back pain.

The TMS diagnosis and treatment protocol are not accepted by the mainstream medical community. However, TMS and Sarno's treatment methods have received national attention, including a segment on ABC's "20/20"; an episode of "Larry King Live"; an interview with "Medscape"; and articles in "Newsweek", "The Seattle Times", and "The New York Times". Prominent medical doctors who support TMS treatment include Andrew Weil and Mehmet Oz. Notable patients treated for tension myositis syndrome include Senator Tom Harkin, John Stossel, Howard Stern, and Anne Bancroft.

Dissociative fugue, formerly fugue state or psychogenic fugue, is a dissociative disorder. It is a rare psychiatric disorder characterized by reversible amnesia for personal identity, including the memories, personality, and other identifying characteristics of individuality. The state can last days, months or longer. Dissociative fugue usually involves unplanned travel or wandering, and is sometimes accompanied by the establishment of a new identity. It is a facet of dissociative amnesia, according to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

After recovery from fugue, previous memories usually return intact. Because of this, there is not normally any treatment necessary for people who have been in fugue states. Additionally, an episode of fugue is not characterized as attributable to a psychiatric disorder if it can be related to the ingestion of psychotropic substances, to physical trauma, to a general medical condition, or to dissociative identity disorder, delirium, or dementia. Fugues are precipitated by a series of long-term traumatic episodes. It is most commonly associated with childhood victims of sexual abuse who learn over time to dissociate memory of the abuse (dissociative amnesia).

Symptoms of a dissociative fugue include mild confusion, and once the fugue ends, possible depression, grief, shame and discomfort. People have also experienced a post-fugue anger.

Atypical facial pain (AFP) is a type of chronic facial pain which does not fulfill any other diagnosis. There is no consensus as to a globally accepted definition, and there is even controversy as to whether the term should be continued to be used. Both the International Headache Society (IHS) and the International Association for the Study of Pain (IASP) have adopted the term persistent idiopathic facial pain (PIFP) to replace AFP. In the 2nd Edition of the International Classification of Headache Disorders (ICHD-2), PIFP is defined as "persistent facial pain that does not have the characteristics of the cranial neuralgias [...] and is not attributed to another disorder." However, the term AFP continues to be used by the World Health Organization's 10th revision of the International Statistical Classification of Diseases and Related Health Problems and remains in general use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments.

The main features of AFP are: no objective signs, negative results with all investigations/ tests, no obvious explanation for the cause of the pain, and a poor response to attempted treatments. AFP has been described variably as a medically unexplained symptom, a diagnosis of exclusion, a psychogenic cause of pain (e.g. a manifestation of somatoform disorder), and as a neuropathy. AFP is usually burning and continuous in nature, and may last for many years. Depression and anxiety are often associated with AFP, which are either described as a contributing cause of the pain, or the emotional consequences of suffering with unrelieved, chronic pain. For unknown reasons, AFP is significantly more common in middle aged or elderly people, and in females.

Atypical odontalgia (AO) is very similar in many respects to AFP, with some sources treating them as the same entity, and others describing the former as a sub-type of AFP. Generally, the term AO may be used where the pain is confined to the teeth or gums, and AFP when the pain involves other parts of the face. As with AFP, there is a similar lack of standardization of terms and no consensus regarding a globally accepted definition surrounding AO. Generally definitions of AO state that it is pain with no demonstrable cause which is perceived to be coming from a tooth or multiple teeth, and is not relieved by standard treatments to alleviate dental pain.

Depending upon the exact presentation of atypical facial pain and atypical odontalgia, it could be considered as craniofacial pain or orofacial pain. It has been suggested that, in truth, AFP and AO are umbrella terms for a heterogenous group of misdiagnosed or not yet fully understood conditions, and they are unlikely to each represent a single, discrete condition.

While psychogenic pain and pain disorder are accepted diagnoses in the medical community, the TMS modality is more controversial.

A non-peer-reviewed 2005 study by Schechter at the Seligman Medical Institute (SMI), co-authored with institute director Arthur Smith, found that treatment of TMS achieved a 57% success rate among patients with chronic back pain.

A peer-reviewed 2007 study with Schechter, Smith and Stanley Azen, Professor and Co-Director of Biostatistics in the Department of Preventative Medicine at the USC Keck School of Medicine, found a 54% success rate for treatment of TMS ("P"<.00001). The treatment consisted of office visits, at-home educational materials, writing about emotional issues and psychotherapy. The average pain duration for the study's patients was 9 years. Patients with less than 6 months of back pain were excluded to "control for the confounder that most back pain episodes typically resolve on their own in a few weeks."

Schechter, Smith and Azen also compared their results to the results of three studies of other psychological treatments for chronic back pain. The three non-TMS studies were selected because of (a) their quality, as judged by the Cochrane Collaboration, and (b) the similarity of their pain measurements to those used in the TMS study. Of the three non-TMS studies, only one (the Turner study) showed a statistically significant improvement. Compared to the 2007 TMS study, the Turner study had a lower success rate (26%-35%, depending on the type of psychological treatment) and a lower level of statistical significance ("P"<.05).

Schechter, "et al." state that one advantage of TMS treatment is that it avoids the risks associated with surgery and medication, but they caution that the risks of TMS treatment are somewhat unknown due to the relatively low number of patients studied so far.

Parcopresis can be described as "an inability to defecate when other people are perceived or likely to be around (e.g. in the same public toilet, house or building)". This inability restricts the sufferer's lifestyle by requiring that s/he defecate only in a limited number of 'safe' places, with less severe presentations also permitting defecation in places where the person is unknown and unlikely to become known in the future, such that any embarrassment is unlikely to have consequences lasting beyond the defecative episode itself (in effect a mundane application of the reasoning that the "game" in question is non-iterative). The level of restriction varies depending on the severity of each sufferer's condition but in extreme cases it can force people to give up their jobs, avoid holidays they would love to take, and generally dictate and limit most aspects of their lives.

It affects both men and women, of all ages and backgrounds. It is not clear how many people suffer with the condition, and level of severity is a key factor as some people may not find it affects their lives, while others find their lives are dictated by its demands.

Parcopresis, also termed psychogenic fecal retention, is the inability to defecate without a certain level of privacy. The level of privacy involved varies from sufferer to sufferer. The condition has also been termed shy bowel. This is to be distinguished from the embarrassment that many people experience with defecation in that it produces a physical inability, albeit of psychological origin.

Parcopresis is not a medically recognized condition.

The lifetime prevalence of dissociative disorders varies from 10% in the general population to 46% in psychiatric inpatients. Diagnosis can be made with the help of structured interviews such as the Dissociative Disorders Interview Schedule (DDIS) and the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D), or with the Dissociative Experiences Scale (DES) which is a self-assessment questionnaire. Some diagnostic tests have also been adapted and/or developed for use with children and adolescents such as the Children's Version of the Response Evaluation Measure (REM-Y-71), Child Interview for Subjective Dissociative Experiences, Child Dissociative Checklist (CDC), Child Behavior Checklist (CBCL) Dissociation Subscale, and the Trauma Symptom Checklist for Children Dissociation Subscale.

There are problems with classification, diagnosis and therapeutic strategies of dissociative and conversion disorders which can be understood by the historic context of hysteria. Even current systems used to diagnose DD such as the DSM-IV and ICD-10 differ in the way the classification is determined. In most cases mental health professionals are still hesitant to diagnose patients with Dissociative Disorder, because before they are considered to be diagnosed with Dissociative Disorder these patients have more than likely been diagnosed with major depression, anxiety disorder, and most often post-traumatic disorder.

An important concern in the diagnosis of dissociative disorders is the possibility that the patient may be feigning symptoms in order to escape negative consequences. Young criminal offenders report much higher levels of dissociative disorders, such as amnesia. In one study it was found that 1% of young offenders reported complete amnesia for a violent crime, while 19% claimed partial amnesia. There have also been incidences in which people with dissociative identity disorder provide conflicting testimonies in court, depending on the personality that is present.

Traumatic grief or complicated mourning are conditions where both trauma and grief coincide. There are conceptual links between trauma and bereavement since loss of a loved one is inherently traumatic. If a traumatic event was life-threatening, but did not result in death, then it is more likely that the survivor will experience post-traumatic stress symptoms. If a person dies, and the survivor was close to the person who died, then it is more likely that symptoms of grief will also develop. When the death is of a loved one, and was sudden or violent, then both symptoms often coincide. This is likely in children exposed to community violence.

For C-PTSD to manifest, the violence would occur under conditions of captivity, loss of control and disempowerment, coinciding with the death of a friend or loved one in life-threatening circumstances. This again is most likely for children and stepchildren who experience prolonged domestic or chronic community violence that ultimately results in the death of friends and loved ones. The phenomenon of the increased risk of violence and death of stepchildren is referred to as the Cinderella effect.

Neurological cause of psychogenic amnesia is controversial. Even in cases of organic amnesia, where there is lesion or structural damage to the brain, caution must still be taken in defining causation, as only damage to areas of the brain crucial to memory processing is it possible to result in memory impairment. Organic causes of amnesia can be difficult to detect, and often both organic cause and psychological triggers can be entangled. Failure to find an organic cause may result in the diagnosis that the amnesia is psychological, however it is possible that some organic causes may fall below a threshold of detection, while other neurological ails are thought to be unequivocally organic (such as a migraine) even though no functional damage is evident. Possible malingering must also be taken into account. Some researchers have cautioned against psychogenic amnesia becoming a 'wastebasket' diagnosis when organic amnesia is not apparent. Other researchers have hastened to defend the notion of psychogenic amnesia and its right not to be dismissed as a clinical disorder. Diagnoses of psychogenic amnesia have dropped since agreement in the field of transient global amnesia, suggesting some over diagnosis at least. Speculation also exists about psychogenic amnesia due to its similarities with 'pure retrograde amnesia', as both share similar retrograde loss of memory. Also, although no functional damage or brain lesions are evident in the case of pure retrograde amnesia, unlike psychogenic amnesia it is not thought that purely psychological or 'psychogenic triggers' are relevant to pure retrograde amnesia. Psychological triggers such as emotional stress are common in everyday life, yet pure retrograde amnesia is considered very rare. Also the potential for organic damage to fall below threshold of being identified does not necessarily mean it is not present, and it is highly likely that both psychological factors and organic cause exist in pure retrograde amnesia.

Occlusal factors as an etiologic factor in TMD is a controversial topic. Abnormalities of occlusion (problems with the bite) are often blamed for TMD but there is no evidence that these factors are involved. Occlusal abnormalities are incredibly common, and most people with occlusal abnormalities do not have TMD. Although occlusal features may affect observed electrical activity in masticatory muscles, there are no statistically significant differences in the number of occlusal abnormalities in people with TMD and in people without TMD. There is also no evidence for a causal link between orthodontic treatment and TMD. The modern, mainstream view is that the vast majority of people with TMD, occlusal factors are not related. Theories of occlusal factors in TMD are largely of historical interest. A causal relationship between occlusal factors and TMD was championed by Ramfjord in the 1960s. A small minority of dentists continue to prescribe occlusal adjustments in the belief that this will prevent or treat TMD despite the existence of systematic reviews of the subject which state that there is no evidence for such practices, and the vast majority of opinion being that no irreversible treatment should be carried out in TMD (see Occlusal adjustment).

Psychogenic amnesia is defined by the presence of retrograde amnesia (the inability to retrieve stored memories leading up to the onset of amnesia), and an absence of anterograde amnesia (the inability to form new long term memories). Access to episodic memory can be impeded, while the degree of impairment to short term memory, semantic memory and procedural memory is thought to vary among cases. If other memory processes are affected, they are usually much less severely affected than retrograde autobiographical memory, which is taken as the hallmark of psychogenic amnesia. However the wide variability of memory impairment among cases of psychogenic amnesia raises questions as to its true neuropsychological criteria, as despite intense study of a wide range of cases there is little consensus of which memory deficits are specific to psychogenic amnesia.

Past literature has suggested psychogenic amnesia can be 'situation-specific' or 'global-transient', the former referring to memory loss for a particular incident, and the latter relating to large retrograde amnesic gaps of up to many years in personal identity. The most commonly cited examples of global-transient psychogenic amnesia are 'fugue states', of which there is a sudden retrograde loss of autobiographical memory resulting in impairment of personal identity and usually accompanied by a period of wandering. Suspected cases of psychogenic amnesia have been heavily reported throughout the literature since 1935 where it was reported by Abeles and Schilder. There are many clinical anecdotes of psychogenic or dissociative amnesia attributed to stressor ranging from cases of child sexual abuse to soldiers returning from combat.