What Do Primary and Secondary Mean?

In medicine, “primary” is used to describe a condition that’s not caused by a different medical condition, while “secondary” means it is a consequence of another condition. For example, someone with secondary insomnia may have trouble falling asleep because of pain, stress, or acid reflux that occurs when they lie down. Someone with primary insomnia simply has difficulty falling asleep and it’s not caused by another medical condition.

Chronic Primary Pain

The ICD-11 defines chronic primary pain as pain that:

  • Is in one or more region of the body
  • Persists for longer than three months
  • Is associated with significant emotional distress or functional disability
  • Cannot be explained by another chronic condition

This includes pain syndromes that are generally thought of as conditions in their own right. Subtypes of chronic primary pain all have to meet those criteria. The ICD-11 subtypes include:

  • Widespread pain
  • Complex regional pain syndrome
  • Chronic primary headache and orofacial (mouth and face) pain
  • Chronic primary visceral (internal organ) pain
  • Chronic primary musculoskeletal pain
  • Other specified chronic primary pain
  • Unspecified chronic primary pain

Chronic Secondary Pain

Chronic secondary pain isn’t a diagnosis on its own but instead an umbrella term for all the categories of nonprimary pain. These include:

  • Chronic cancer-related pain
  • Chronic postsurgical or post-traumatic pain
  • Chronic secondary musculoskeletal pain
  • Chronic secondary visceral pain
  • Chronic neuropathic pain
  • Chronic secondary headache or orofacial pain