Pain can be split 2 types known as neuropathic or nociceptive. The difference between the two types exist in the mechanism of the pain.

 

 

Nociceptive pain

This is further divided into somatic and visceral:

 

Somatic pain:

 

Somatic pain commonly arises from soft tissue structures such as skin and connective tissues, bones, joints and muscles which is described as a throbbing and aching pain.

The neuronal pathways remains normal and pain is localised as patients can often point to the exact area where the pain is arising from. Examples of somatic pain include bone metastatic cancer.

 

Visceral pain:

 

Visceral pain is described as aching or intermittent cramping and patients commonly find  it difficult to pinpoint  where the pain is arising from e.g. in  pancreatic cancer or metastatic cancer to the liver.

This type of pain may result from compression or distension of the thoracic or abdominal viscera including organs such as the liver, bowel or heart. 

 

 

 

Neuropathic pain

 

This type of pain arises from nerve damage and so abnormal neurones fire electrical impulses spontaneously and react in a different manner to normal stimuli. This is further divided into 2 types known as continous dysesthesias and lancinating pain.  

 

Continous dysesthesias is described as persistent burning pain, whereas the latter is chronic shooting pain which is sudden in onset and exacerbated by movement. In addition, allodynia and hyperalgisia is associated with neuropathic pain. This is where there is altered pain perception and harmless stimulus may elicit pain and  there is increased sensitivity to painful stimulus.

 

Breakthrough pain

 

This type of pain affects 50% of patients with cancer and can severely affect the quality of life experienced by patients.

 

This is a sudden increase in the intensity of pain or commonly referred to as ''flare ups''.  There are 3 types of breathrough pain;

 

• End of dose failure: this type of pain commonly occurs prior to the next dose of analgesic and is gradual in onset. Physicians may consider shortening the periods between doses or increasing the analgesic dose.

 

• Spontaneous pain as the name suggests has no known cause and therefore can be unpredictable in onset. 

 

• Incident pain is excacerbated with movement i.e. walking and is therefore predictable so analgesia can be provided prior to activity to relieve pain.