Dictionary > Hyperalgesia


The excessive sensitivity to pain
Hyperalgesia pertains to the excessive sensitivity to pain. It is often associated with damaged nerve cells, such as nociceptors (i.e. sensory receptors responsible for detecting or responding to pain).
Hyperalgesia may also be induced by platelet-activating factor associated with inflammatory response of the body. The immune cells interact with the peripheral nervous system resulting in the release of cytokines and chemokines.1
Hyperalgesia may be experienced in focal areas or may be diffuse, i.e. affecting the body. It may be primary or secondary. A primary hyperalgesia is a type of hyperalgesia in which the pain sensitivity occurs directly in the damaged tissues. A secondary hyperalgesia is one in which the pain sensitivity occurs in surrounding undamaged tissues.
An example of hyperalgesia is opioid-induced hyperalgesia. Opioid treatments of chronic pain followed by opioid withdrawals may lead to hyperalgesia. The discontinuation of pain treatment may extremely activate the pain pathways in the nervous system.
Word origin: Greek hupér (“over”) + Greek algesis (pain)

  • hyperalgia


  • hypoalgesia
  • See also:

    Mentioned in:

  • Afferent nerve
  • Reference(s):

    1 Marchand F, Perretti M, McMahon SB (July 2005). “Role of the immune system in chronic pain”. Nat. Rev. Neurosci. 6 (7): 521–32.

    You will also like...

    Neurology of Illusions
    Neurology of Illusions

    Illusions are the perceptions and sensory data obtained from situations in which human error prevents us from seeing the..

    running freshwater community
    Running Water Freshwater Community Factors

    This tutorial noted some of the physical and chemical factors that provide the framework of a running water community in..

    Hormone Production
    Hormone Production

    Hormones are chemical messengers produced by specialized glands and they were produced by switching on the genes designe..

    genes controlling growth and development
    Control of Growth & Development

    Control of Growth & Development tutorials look at how the genetic makeup determines the biological processes on a da..

    Protein (illustration)
    Protein Variety

    The sequence of amino acids determines the type of protein. Protein is synthesized according to the sequence of nucleoti..

    Origins of Life on Earth
    Origins of Life on Earth

    Earth was created around 4.5 billion years ago and life began not long after. Primitive life likely possessed the elemen..