Clinicians are taught that patients will present with symptoms (subjective complaints) and signs (objective findings) that suggest the presence of a pathophysiological process. They are trained to recognize these presentations and to diagnose the underlying disease so that they may institute the appropriate treatment. Satisfaction for the care provider arises from the ability to perform these tasks proficiently and see the patient benefit. Patients typically come to the clinician’s office seeking an explanation for and relief from their symptoms. Difficulties arise in the relationship when the patient presents with symptoms and the clinician can find no disease to explain them. Symptoms that lack discernible physical pathology have been referred to variously as medically unexplained, functional, or somatization.

The term somatization (as used in this chapter) refers to the experience and reporting of physical symptoms that cause distress but that lack a corresponding level of tissue damage or pathology and are linked to psychosocial stress. In contrast to this broad and inclusive view of the process, psychiatrists have developed strict diagnostic criteria that define several distinct disorders, which are collectively referred to as the somatic symptom and related disorders. As such, clinicians should be careful to distinguish between somatization, as defined above, and somatization disorder, which is one type of somatic symptom disorder. In general, these latter conditions are chronic and reflect an enduring way for the affected individuals to cope with psychosocial stressors. However, it is much more common in the primary care setting to encounter patients who have somatization symptoms but do not meet the full criteria for a psychiatric diagnosis. In many individuals, the somatization might be a transient phenomenon during a particularly stressful period such as divorce proceedings, consisting of an exaggeration of common physical symptoms such as headache. In other patients, the process may be more persistent and the symptoms may be disabling. The latter group of patients can be particularly difficult for clinicians. Although their symptoms are suggestive of an underlying medical or neurologic condition, no such etiology is discovered upon appropriate diagnostic evaluation. Some patients do find reassurance in the provider’s statements that no medical cause for their symptoms has been found. Other patients may become upset and accuse the clinician of not believing them or of being incompetent. Some patients insist on continued diagnostic testing or referral to specialists. Further, the symptoms do not respond to standard medical treatments; this therapeutic failure can lead to requests for more testing, referrals, or different treatment regimens. The combination of increasing demands made by patients and their lack of response to treatment can be very frustrating for the clinician.

The existence of medically unexplained symptoms has been recognized throughout the history of medicine. Each historical period has described syndromes composed of such symptoms. The scientific knowledge and theories of the time have shaped the etiologies proposed for these disorders. The treatments advocated by medical practitioners were directed at attempting to correct the abnormality assumed to cause the illness. Each of these syndromes shared the recognition by medical authorities of the time that the illness lacked the demonstrable, pathologically defined tissue changes that characterize most medical conditions.

Before the Renaissance, medical theories were based on limited understanding of anatomy or physiology and, as a result, seem quite primitive to modern practitioners. Diseases lacking an apparent cause were believed to result from gross disturbances in the function and behavior of bodily organs. For example, hysteria, an earlier conceptualization of somatization, was attributed to a “wandering uterus” as early as 1900 bc. The treatments for hysteria flowed from this conceptual model and included the application of ointments to the labia or manipulation of the uterus to return it to its “natural” position. It was not until after the Renaissance that medical practitioners began to implicate disturbances of the nervous system in the genesis of medically unexplained symptoms. However, despite this change in the understanding of these disorders, the treatments utilized by clinicians did not become significantly more advanced. For instance, some practitioners in the latter half of the seventeenth century advocated hitting patients who had symptoms of hysteria with a stick.

By the end of the seventeenth century, and continuing into the eighteenth century, clinicians increasingly recognized the role psychological factors played in the origin and maintenance of somatic symptoms. For example, Thomas Sydenham attributed conditions such as pain, convulsions, and diarrhea to a disordered mind. More importantly, the treatments for these symptoms were beginning to reflect this appreciation. Medical authorities no longer focused exclusively on somatic therapies in the care of afflicted individuals. Instead, practitioners were encouraged to inquire about and demonstrate an active interest in their patients’ mental state and welfare. Further, clinicians recognized the need to attempt to promote optimism about recovery in their patients.

In the nineteenth century, there was awareness that despite many advances in the understanding of pathology, patients suffering from somatization syndromes lacked discernible anatomic abnormalities. As a result, the medically unexplained disorders were attributed to a subtle or “functional” pathological disturbance. This explanatory model of illness was associated with a return to predominantly somatic interventions for treating the symptoms. However, some practitioners maintained that psychological treatments were important for managing these patients. These clinicians also recognized that unless the therapy was delivered in a way that was consistent with the patients’ belief that their illness had a physical etiology, the intervention would be rejected. Paul Briquet, in his seminal Treatise on Hysteria (1859) described the in-depth study of over 400 patients with “hysteria” during a 10-year period and emphasized that the treatment of such patients addresses social and environmental problems.

At the turn of the twentieth century, an exclusively psychological model for these disorders was developed. The idea of a functional pathological lesion of the nervous system was replaced with the concept of psychogenesis (i.e., the somatization symptoms arose from the mind). Somatization was viewed as the means by which unconscious mental conflicts could be manifested in the form of physical symptoms. As a result, mental health practitioners became responsible for the diagnosis and treatment of these disorders. However, the idea of physical complaints originating from the mind was also associated with implications that the symptoms were not “real.” Further, many patients were not convinced of the value of this interpretation of illness.

Medically unexplained syndromes have persisted as clinical problems for practitioners. Patients often present with many symptoms that are not associated with abnormalities demonstrable by physical examination or laboratory or radiological studies. The symptoms are often clustered together as syndromes with a variety of proposed etiologies including environmental exposures, infections (e.g., Candida, Epstein–Barr virus), or multiple chemical sensitivity. In addition, the broad range of advocacy and educational groups that try to promote various agendas with regard to the disorders can make the evaluation of these syndromes difficult.

Somatization can be understood from a number of different perspectives, each of which proposes a cause for the symptoms. However, because the precise cause of these symptoms is not known, none of the following theories are fully explanatory. Rather, each view of somatization provides practitioners with insight into the genesis of these symptoms and suggests possible treatments as well. Unfortunately, each model is able to explain the symptoms of only a select group of patients. A more comprehensive understanding of patients comes from incorporating more than one perspective.

Neurobiological

According to the neurobiological perspective, somatization symptoms result from dysfunction in the neuroendocrine systems responsible for processing peripheral sensory and central emotional information. As a result, the affected individual misinterprets normal bodily sensations or emotional signals as indicating a dangerous somatic process. The mechanism is unknown by which dysfunction in the nervous or endocrine systems results in the preoccupation with somatic symptoms. There is growing evidence of the role of such abnormalities in these disorders. For example, researchers have recently suggested that hypocortisolism plays a role in posttraumatic stress disorder, fibromyalgia, chronic fatigue syndrome, and some chronic pain disorders. Although hypocortisolism has been found in groups of individuals with the above diagnoses, the relationship between a deficiency of cortisol and the production of these symptoms is not well understood. Additional research has examined the inability of individuals with somatization symptoms to habituate to novel stimuli. Individuals with somatization syndrome reported higher levels of tension in novel situations and were less likely to habituate to the situation over time. In addition, the affected individuals had a slower return to baseline heart rate upon leaving stressful situations. These studies suggest a relationship between physiologic mechanisms involved in adapting to novel or stressful stimuli and the apparently psychological symptoms of individuals with somatic symptom disorders.

Psychodynamic

According to psychodynamic theory, somatic symptoms arise solely from the mind. They are believed to represent the outward expression of underlying, internal psychological conflicts. Studies have demonstrated that individuals with somatization have higher rates of prior emotional and physical abuse, depression, and anxiety than nonaffected populations. It is hypothesized that abuse places individuals at risk for the types of internal conflicts that result in somatic symptom disorders. For example, women who have suffered sexual abuse in childhood have increased rates of chronic pelvic pain when compared with those without a history of abuse. Depression and anxiety may be both a product and cause of these internal conflicts. Patients with somatic symptom disorders may be less able to correctly interpret emotional arousal and instead identify these signals as physical symptoms. This is further supported by studies that demonstrate a link between alexithymia, or the inability to identify and verbally describe emotions and feelings in oneself or others, and somatic symptom disorders. Other findings suggest that childhood trauma in women is associated with higher levels of somatization, mediated by the development of insecure attachment. Attachment theory predicts how individuals’ interactions in interpersonal relationships are influenced by early experiences with caregivers. A four-category model has been proposed, which describes four different types of attachment: secure, preoccupied, dismissive, and fearful. In particular, research examining the role of attachment style and its link to somatization and subsequent health care utilization has found that patients with preoccupied attachment, where the individual tends to idealize others, is less self-reliant and needs more reassurance; and fearful attachment, where the individual may be less trusting of others as well as less self-reliant, are more likely to be high in somatic symptom reporting and are higher users of medical resources.

Cognitive Behavioral

According to cognitive behavioral theorists, in somatic symptom disorders, symptoms arise from incorrect beliefs about bodily sensations, for example, the belief that mild gastroesophageal reflux (or panic symptoms) represents myocardial ischemia. These misinterpretations, in turn, result in certain maladaptive behaviors, such as going from one emergency room to another seeking evaluation of the symptom and reassurance that the heart is functioning normally. These symptoms are reinforced by factors in the individual’s environment such as the responses of other people to the perceived illness. For instance, the affected individual may be excused from work or social obligations. As an example of this process, some researchers proposed that learning about a disease may lead certain individuals to attribute previously overlooked symptoms to the illness. The affected person seeks out confirmatory evidence of additional symptoms that both reinforce the belief in the illness and amplify the somatic symptoms. The person’s self-validating review of symptoms may be augmented by contact with advocacy or educational groups that promote awareness of the disease. The processing of bodily information gradually becomes colored by the belief that the person has a disease, and this can result in the affected individual embracing the sick role.

Sociocultural

According to the sociocultural perspective, individuals learn to express disease and distress in culturally sanctioned ways. In any culture, the expression of certain bodily symptoms and illness behaviors are encouraged whereas others are discouraged. Although somatization is a universal process, an individual’s culture can affect the manner in which somatic representations of emotional distress are utilized. Further, this theory maintains that because the patient and the clinician are often from different backgrounds, the cultural interaction between the clinician and the patient is important. This interaction often determines how the patient’s symptoms are experienced, interpreted, and reported. The clinician’s task in these meetings is to correctly recognize which of the patient’s somatic complaints represent cultural idioms of emotional distress. Mistakes in this assessment can lead to misdiagnosis, unnecessary medical treatment, or evaluation, frustration on the part of the provider when the patient does not respond as expected, and patient dissatisfaction.

Although the theoretical models discussed above have evidence to support them and have been used as the basis for treatment in cases of somatization, there is another way to conceptualize somatization and the associated disorders. This view begins with the clinician abandoning the either–or categories of “physical” and “psychological.” This dichotomous framework leads to interactions in which the patient can feel that the clinician is rejecting them and the reality of their symptoms by concluding, “The doctor’s saying it’s all in my head.” Instead, the provider adopts a more comprehensive view of disease based on the biopsychosocial model of illness that includes key elements from other explanatory models. In this paradigm, all illnesses are understood to have biological, psychological, and sociocultural dimensions.

Although the western medical model focuses on the biological aspects of disease, it often ignores the psychological and sociocultural facets of the patient’s experience. In addition, this model, often very effective for understanding and treating acute disease processes, may fail to explain much of the complexity of chronic illness. For example, pain researchers have found that psychological factors are more important than physical factors in predicting future disability. Such research has led to the development of new treatment paradigms that recognize the interplay between the biological disease process and the psychosocial impact of symptoms. Treatment is focused on both relieving the biomedical symptoms and modifying the thoughts, feelings, and behaviors associated with the pain and disability.

Using the more comprehensive biopsychosocial model, illness can be understood as occurring along a spectrum with disorders characterized by predominantly somatic problems at one end and disorders with predominantly psychological or social manifestations at the other. Therefore, evaluation of patients should routinely include inquiries into both the physical and psychosocial dimensions of their illness. With this biopsychosocial framework, the somatic symptom disorders are seen as arising when the patient neglects the psychosocial components of his/her illness and focuses on viewing the problem solely from a somatic perspective. For example, an individual with a history of chronic pelvic pain who has undergone multiple thorough evaluations with no identified anatomic etiology but who insists on repeating the workup rather than discussing psychosocial facets of the symptoms may be experiencing somatization. According to this model, symptom amplification, a phenomenon seen commonly in somatization, may arise when the experience of these symptoms is modified by psychosocial factors. This is illustrated in Figure 28-1, where these factors are represented by a psychosocial lens, which alters the “image” of the stimulus (somatic symptoms), resulting in a magnified image (effect), or increased experience of these symptoms. Somatization itself is not a single entity. Like most illnesses it can be understood to have a continuum of expression. At one end is the transient, stress-related exaggeration of common physical symptoms and at the other are the serious, persistent complaints that leave the patient disabled.