More than half of the days lost due to sickness absence are due to diagnostic groups that solely or mainly depend on subjective statements from the patient The most frequent subjective health complaints are musculoskeletal pain. These conditions do not seem to qualify as psychiatric or mental disorders, but are not strictly somatic states either. Terms like somatization may be inadequate terms for states that may be best understood as psychobiological feedback loops. Subjective health complaints is suggested as a neutral, descriptive term. Only a minority requires treatment and sickness compensation for prolonged periods for these very common states. In these patients the neurons in feed-forward and positive feedback loops may have developed sensitization. These patients tend to show an abnormal sensitivity to sensory input from muscles, the gastrointestinal tract, and to smell and taste. It seems to be futile to search for single-factor solutions. This approach opens up for the possible effectiveness of many different types of treatment, breaking the feedback loops.