Symptoms are subjective bodily sensations or mental experiences that are perceived as indicative of a change in health, due to an illness, injury or disease. Often symptoms have no obvious cause, and in the absence of treatment, can be very distressing. When symptoms appear to lack an organic cause or exceed what would be expected from an illness, people are thought to be suffering from ‘persistent somatic symptoms’ (PSS). This is common in both primary care and specialised medicine and is associated with increased disability and use of healthcare services. Together with Dutch researchers, we are working on the development of a questionnaire to assess such symptoms.