Psychologic symptoms may also be a reaction to a physical disorder. Physical symptoms may be due to psychologic stress. The term psychosomatic can diffusely encompass these possibilities, emphasizing that emotional disturbances and psychologic factors are ubiquitously interrelated with physical disease and disability. The stressful events and psychologic reactions may be viewed as precipitants. The psychologic reactions are nonspecific and may be associated with a wide variety of disorders, such as diabetes mellitus, SLE, leukemia, and multiple sclerosis.
Psychologic stress can precipitate or alter the course of even major physical disorders.
Emotions obviously can affect the autonomic nervous system and, secondarily, cardiac rate, sweating, or bowel peristalsis. The pathways and mechanisms by which the brain and immune system interact remain unclear, but a connection is suggested by nerve terminals found in the spleen and thymus near lymphocytes and macrophages that have receptors for neurotransmitters. Psychologic factors may indirectly influence the course of various disorders. Commonly, a patient's need to deny illness or the seriousness of an illness may lead to noncompliance with therapy or use of alternative or complementary medicine. In diabetes, for example, a patient may become depressed because of his endless dependence on insulin injections and careful dietary management and may therefore deny the need for them and neglect therapy.