OBJECTIVES: To estimate the prevalence of nonarticular pain complaints (chronic widespread pain, chronic localized pain, transient pain) and fibromyalgia in hospitalized patients and to study utilization patterns of health services associated with pain related problems. METHODS: Five hundred twenty-two patients hospitalized on internal medicine wards were enrolled. Data were collected with a questionnaire covering demographic background, information on pain and other symptoms, utilization of health services, and drug consumption. All subjects were classified into four pain groups: those with no pain, transient pain, chronic regional pain, and chronic widespread pain. Tenderness was assessed by thumb palpation, and patients were diagnosed as having fibromyalgia if they met the 1990 American College of Rheumatology criteria. RESULTS: Sixty-two percent of the patients reported pain; 36% reported chronic regional pain, 21% reported chronic widespread pain, and 5% reported transient pain. Fifteen percent of all patients had fibromyalgia, most of whom (91%) were women. The prevalence of chronic widespread pain and of fibromyalgia in women increased with age. Sleep problems, headache, and fatigue were highly prevalent, especially among those with chronic widespread pain. Patients with chronic widespread pain reported more visits to family physicians (6.2 visits per year) and more frequent use of drugs. They also were more frequently referred to rheumatologists, and they reported more hospitalizations. CONCLUSIONS: Pain syndromes and related symptoms are prevalent among hospitalized patients on the medicine wards. The internist taking care of these patients should be aware of the presence of these syndromes and realize that some of the reported symptoms are partly related to these (undiagnosed) pain syndromes rather than to the cause of hospitalization.