We are all familiar with pain. Naturally it's
something we want to avoid. But pain does have a positive role -- it warns us
when we're in danger, sick or injured so that we can take evasive action or seek
Our ability to feel pain is part of the way we interact with the workings of
our bodies and interact with the outside world. Through experiencing pain and
recalling the event, we learn to avoid things that are potentially harmful and
In fact, feeling pain is vital to our well-being. This is evident when the
whole body or parts of it lose the ability to detect the pain sensation. In
leprosy sufferers, for example, the nerves to the hands and feet are often
damaged and, as a result, they continually injure their hands and feet without
feeling any pain.
The type of pain we experience depends on what is causing it. It also depends on
the way in which pain signals are interpreted and analysed by the nervous
system. For instance, if you're seriously ill, severe pain can arise from the
persistent presence of some harmful stimulus in our bodies. But it can also
occur as a result of a malfunction of the nerve fibres that relay our pain
Though pain is distressing, it can provide a vital clue to diagnosis. The
type of pain, its character and the position can enable doctors to detect the
cause of the complaint and decide on suitable treatment.
THE PAIN ROUTE
Pain messages are triggered by painful stimuli both inside and outside our
bodies. These stimuli excite unspecialized nerve endings in the skin and
The nerve endings are attached to two types of nerves that connect with the
spinal cord, the organ responsible for the initial analysis of our pain
sensations. One type of these nerve endings will relay information very rapidly,
the other less so. This helps us to distinguish between two types of pain: that
which needs to be reacted to immediately, such as a burning pain, and that which
doesn't, such as a dull ache.
The nerve endings continue to make contact with the network of nerve fibres
in the spinal cord until the information is more organized.
It is then relayed to the thalamus, the special area in the brain which
processes information from skin receptors. The thalamus sends the message on to
the cerebral cortex which makes the final analysis. The brain also considers our
emotional state before it finally decides how to perceive the painful stimuli.
NOT ALL THE SAME
There are different types of pain. For instance, skin pain is usually localized
and may be of a pricking or burning quality. Internal pain is more variable, but
tends to be less localized and is perceived as deeper and often duller.
'Referred pain' originates in one organ or area but is felt in another. This
is because the messages from these organs are received and analysed by parts of
the spinal cord that also deal with the areas where the pain seems to be coming
from.For example, pain coming from the heart may be felt in the chest but also
in the jaw and left arm, as the pain messages spill over in their spinal
analysing centres into neighbouring zones.
When an arm or a leg has been amputated, the nerves remain in the stump.
Initially, the brain will register pain from the stump as if it were coming from
the lost limb. This phenomenon is known as `phantom pain'. After a while,
however, the brain usually reorganizes its perceptions so that any pain felt
from the stump actually comes from there.
ALL IN THE MIND?
Your state of mind is an important factor in your perception of pain. For
example, a soldier who has been seriously injured in battle may feel no pain
because his mind is focused on fighting. When the battle is over, the pain may
be unbearable, even though the injury is exactly the same.
In India, practitioners of yoga are able to avert their minds from pain by
contemplating other things. As a result, they can achieve great feats of
endurance, such as lying on a bed of nails. In cases like this, it's thought the
brain is somehow prevented from acknowledging the unpleasant significance of the
pain messages it receives.
The other side of this coin is the detrimental psychological effects pain can
have on us. Prolonged severe pain progressively erodes our mental ability to
cope with it. As a result, our personality appears to change as we focus more
and more on the pain and perceive it as getting increasingly worse. So it is
therefore wrong to dismiss pain as being only in the mind.