In chronic primary pain syndromes (left), pain can be conceived as a disease, whereas in chronic secondary pain syndromes (right), pain initially manifests itself as a symptom of another disease such as breast cancer, a work accident, diabetic neuropathy, chronic inflammatory bowel disease, rheumatoid arthritis, etc. Differential diagnosis between primary and secondary pain conditions may sometimes be challenging (arrows), but in either case, the patient’s pain needs special care when it is moderate or severe. After spontaneous healing or successful management of the underlying disease, chronic pain may sometimes continue and hence the chronic secondary pain diagnoses may remain and continue to guide treatment as well as healthcare statistics. IASP: International Association for the Study of Pain.
[Adapted from Treede et al. 2019.1]

  1. Treede RD, et al. Pain. 2019;160:19–27.