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in 1995 the British Medical Journal
published an astonishing report about a
29 year old builder he accidentally
jumped onto a 15 centimeter nail which
pierced straight through his steel-toed
boot he was in such agonizing pain that
even the smallest movement was
unbearable but when the doctors took off
his boot
they faced a surprising sight the nail
had never touched his foot at all for
hundreds of years scientists thought
that pain was a direct response to
damage by that logic the more severe an
injury is the more pain it should cause
but as we've learned more about the
science of pain we've discovered that
pain and tissue damage don't always go
hand-in-hand
even when the body's threat signaling
mechanisms are fully functioning we're
capable of experiencing severe pain out
of proportion to an actual injury and
even pain without any injury like the
builder or the well documented cases of
male partners of pregnant women
experiencing pain during the pregnancy
or labor what's going on here there are
actually two phenomena at play the
experience of pain and a biological
process called nociception nociception
is part of the nervous systems
protective response to harmful or
potentially harmful stimuli sensors in
specialized nerve endings detect
mechanical thermal and chemical threats
if enough sensors are activated
electrical signals shoot up the nerve to
the spine and onto the brain the brain
weighs the importance of these signals
and produces pain if it decides the body
needs protection
typically pain helps the body avoid
further injury or damage but there are a
whole set of factors besides nociception
that can influence the experience of
pain and make pain less useful first
there are biological factors that
amplify no susceptibles to the brain if
nerve fibers are activated repeatedly
the brain may decide they need to be
more sensitive to adequately protect the
body from threats more stress sensors
can be added to nerve fibers until they
become so sensitive that even light
touches to the skin spark intense
electrical signals in other cases nerves
adapt to send signals more efficiently
amplifying the message these forms of
amplification are most common in people
experiencing chronic pain which is
defined as pain lasting more than three
months when the nervous system is nudged
into an ongoing state of high alert pain
can outlast physical injury this creates
a vicious cycle in which the longer pain
persists the more difficult it becomes
to reverse psychological factors clearly
play a role in pain to potentially by
influencing nociception and by
influencing the brain directly a
person's emotional state memories
beliefs about pain and expectations
about treatment can all influence how
much pain they experience in one study
children who reported believing that
they had no control over pain actually
experienced more intense pain than those
who believed they had some control
features of the environment matter to in
one experiment volunteers with a cold
rod placed on the back of their hand
reported feeling more pain when they
were shown a red light than a blue one
even though the rod was the same
temperature each time finally social
factors like the availability of family
support can affect perception of pain
all of this means that a multi-pronged
approach to pain treatment that includes
pain specialists physical therapists
clinical psychologists nurses and other
health care professionals is often most
effective we're only beginning to
uncover the mechanisms behind the
experience of pain but there are some
promising areas of research until
recently we thought the glial cells
surrounding neurons were just support
structures but now we know they have a
huge role in influencing nociception
studies have shown that disabling
certain brain circuits in the amygdala
can eliminate pain in rats and genetic
testing in people with rare disorders
that prevent them from feeling pain have
pinpointed several other possible
targets for drugs and perhaps eventually
gene therapy ever wonder how pain
relievers work or how other animals
experience pain check out these lessons
to learn more
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