PAIN - An Unpleasant Sensation

Have you ever thought what PAIN is???

 Usually we never bother to think about the general physical problems. We just feel it and go for its treatment. But have you ever sincerely thought what mechanism would be underlying this uncomfortable physical response called PAIN?

 So grossly if we see, pain is a sensation that hurts, and it has both physical and emotional aspects to consider.

It is a combination of what your body feels and how your mind processes those sensations.

The International Association for the Study of Pain says  that it is "an unpleasant sensory and emotional experience in association with actual or potential tissue damage, or described in terms of such damage."

                   Pain serves a biological function. It signals the presence of damage or disease within the body.

 How is pain produced????

·         Pain is produced when a  nociceptive (a receptor preferentially sensitive to a noxious stimulus)  stimulus  is received.

·         it is stimulated by any of the agents like,cut,blow,acid,burn or disease.and subsequently transmit signals through sensory neurons in the spinal cord.

·         which releases glutamate, a major exicitory neurotransmitter that relays signals from one neuron to another and ultimately to the thalamus, in which pain perception occurs.

·         From the thalamus, the signal travels to the cerebrum, at which point the individual becomes fully aware of the pain.

Interestingly, the brain itself is devoid of nociceptive tissue, and hence cannot experience pain (thus a headache is not pain in the brain itself).

Do you know, pain also has classification??

  1) Fast pain &
  2) Slow pain

Fast pain is felt within about 0.1sec after pain stimulus is applied,

whereas slow pain begins only after 1 sec or more and then increases slowly over many seconds and even some minutes.
 

importantly, it can also be classified as:

 

Pain

                          Nociceptive                               Non-nociceptive

                                                                                          

        Somatic            Visceral                            Neuropathic      Sympathetic

 

Nociceptive  pain  arises from the stimulation of specific pain receptors. These receptors can respond to heat, cold, vibration,stretch and chemical stimuli released from damaged cells.

Non Nociceptive pain  arises from within the peripheral and central nervous system. Specific receptors do not exist here.

 Somatic Pain :  occurs in skin, muscle, joints, bones, and ligaments etc.

It is often sharp and well localized, and can often be reproduced by touching or moving the area or tissue involved.

 Visceral Pain: occurs in  internal organs of the main body cavities. Like, liver, kidneys, spleen, bowels, bladder, womb etc.

 Often poorly localized, and  may feel like a vague deep ache, sometimes being cramping or colicky in nature. It frequently produces referred pain.

 Nerve Pain (neuropathic):  within the nervous system itself.

signs of nerve malfunction such as hypersensitivity (touch, vibration, hot and cold), tingling, numbness, and weakness. There is often referred pain to an area where that nerve would normally supply e.g. sciatica from a slip disc. Nerve pain is often described as lancinating, shooting, burning, and hypersensitive.

 Sympathetic pain: due to over-activity of sympathetic and central / peripheral nervous system mechanisms.

occurs more commonly after fractures and soft tissue injuries of the arms and legs which presents as extreme hypersensitivity in the skin around the injury and also peripherally in the limb, and is associated with abnormalities of sweating and temperature control in the area. The limb is usually so painful, that the sufferer refuses to use it, causing secondary problems after a period of time with muscle wasting, joint contractures, and osteoporosis of the bones.

 

              So, to sum up, Pain is a perception and not an objective bodily state.

           Despite its unpleasantness, pain is a critical component of the body's defense system. It is a part of a rapid warning and defense relay instructing the motor neurons of the central nervous system to minimize detected physical harm.

It is important to understand that pain medicines do not remove all pain; instead, they lessen what the body feels and help the mind accept those feelings.