Chronic pain

Chronic pain has different origins and is often burdensome. Get all key information here.

What is chronic pain?

Having an understanding of pain and its origins has always been a challenge in the history of medicine.

Pain is a significant symptom in the diagnostic process of many diseases as, in many cases, it is an important protective reflex. Pain is defined as an unpleasant, distressing feeling somewhere in the body caused by internal or external factors. Specifically, chronic pain is a type of pain that generally persists in time for over three months. The World Health Organization classifies chronic pain as follows: primary chronic pain, chronic cancer-related pain, post-surgical or post-traumatic chronic pain, neuropathic chronic pain, orofacial pain and headache, chronic visceral pain and, musculoskeletal pain.

In general, pain itself may constitute a disease per se (primary pain) or it may derive from, or be a symptom of, an underlying disease (secondary pain). Primary chronic pain is characterized by a functional disorder or emotional stress, basis that cannot be explained by other causes. It is multifactorial since it involves biological and psychological factors that are intrinsic to the person as well as social factors.

Chronic pain affects between 15–30% of the general adult population, with severe, debilitating chronic pain affecting 10–15% of adults. Low back pain and neck pain are the most common diagnosis in older adults. Pain prevalence increases with age, pain intensity may be highest during midlife (e.g.,45–65 years), when the incidence of severe pain peaks.

Symptoms of chronic pain

Acute pain is usually a warning from our body telling us that something is not right, that there is an injury in a tissue. Chronic pain symptoms are highly variable, and the same patient may experience more than one type of chronic pain, e.g., lumbar pain and also fibromyalgia. In order to properly characterize the type of pain that patients feel, their medical history must show the duration, the location of pain, if it is radiating, if there are factors that help improve or exacerbate pain, its frequency, and its intensity. Pain intensity is usually measured using a 0-10 numerical scale. Furthermore, symptoms associated with the pain itself must also be assessed: muscle spasms or aches, changes in temperature, movement limitations, morning stiffness, changes in muscle strength, changing the perception of sensations.

How long does chronic pain last?

As indicated by its name, chronic pain may last the patient's whole life. However, affected people does not feel continuous and high intensity pain all the time. Also, analgesic treatments help decrease and modulate pain intensity.

Effects of chronic pain

Patients with chronic pain do not only suffer due to the pain itself: they are also more vulnerable to develop psychiatric disorders, such as stress, depression or anxiety, leading to relevant impairment of activities of daily living and quality of life. However, it is important to highlight that chronic pain management has shown to have a positive impact on patients that are also under psychiatric treatment.


1. Raffaeli, W. & Arnaudo, E. Pain as a disease: An overview. J Pain Res 10, 2003– 2008 (2017).

2. Treede RD1, Rief W, Barke A, Aziz Q, Bennett MI, et al. NCBI [Internet]. A classification of chronic pain for IDC-11. 2015 June. Available at: doi: 10.1097/j.pain.0000000000000160

3. Dydyk, A. M., Conermann, T., Campus, A. C. & Network, A. H. Pain , Chronic. (2020).

4. Johnson, Mark I. The Landscape of Chronic Pain: Broader Perspectives. MDPI [Internet] 2019 May. Medicina 2019, 55, 182. Available at: doi: 10.3390/medicina55050182.

5. World Health Organization. WHO guidelines for the pharmacological and radiotherapeutic management of cancer pain in adults and adolescents. 2018 June. Available at: doi: 10.4135/9781446222126.n9.

6. Molton, IR. Terril, AL. Overview of persistent pain in older adults. NCBI [Internet]. 2014 March. Vol. 69, No. 2, 197–207. Availabe at: doi: 10.1037/a0035794.