Occupational health, grounded in occupational medicine, aims to enhance the well-being and labor productivity of the working population. Within this realm, there has been growing concern over the increasing instances of labor loss due to diminished physical capacity and the rise in musculoskeletal disorders. Chronic pain is also associated with musculoskeletal disorders. Another pressing issue related to chronic musculoskeletal pain was needed assistance services are underutilized, is referred to as a "service gap". Understanding trends based on age and affected regions of the body is indispensable for developing strategies to address chronic musculoskeletal pain in workers. This study aimed to elucidate age-specific trends in the prevalence and number of pain sites in chronic musculoskeletal pain as well as the patterns of treatment during chronic musculoskeletal pain, categorized by age and affected site. This study was conducted in December 2022 in contract to Cross Marketing Inc. The survey began on December 12, 2022 and ended on December 15, 2022. An online survey was administered to 1,946 participants (973 women and 973 men), and responses were collected, ensuring a roughly equal distribution of samples among men and women across six age groups ranging from their 20 to 70 s. The survey inquired about the presence of chronic pain in each of the eight body parts and the adoption of five different treatments when experiencing pain. Statistical analysis was performed using the chi-square test, with the measurement data categorized by age group and body part. The results indicated a significantly higher prevalence of chronic pain at three or more sites among individuals in their 30 s: the prevalence of pain at each of the eight body sites varied with age. Approximately half of the participants did not engage in specific treatments during episodes of chronic pain. The presence or absence of treatment showed no significant differences according to affected site or age group. This study revealed age- and body part-related relationships with chronic musculoskeletal pain in middle-aged patients and highlighted healthcare service gaps in its management in Japan.