Understanding Pain

The International Association for the Study of Pain (IASP) defines pain as:
an unpleasant sensory and/or emotional experience associated with
actual or potential tissue damage or described in term of such damage.
Pain is actually a message sent along the nerves to let the brain
know that something is damaging the body. The brain responds by
sending a message to the muscles or organ to take action.
In the medical world, all pain is divided into two categories: acute
pain and chronic pain.
Acute pain is temporary, and goes away quickly. It's useful, since it
usually warns you of sources of harm and tells your body to protect
itself while it's healing.
Chronic pain is pain that is unpleasant and lasts for prolonged
periods of time. Generally if you've been experiencing pain in the
same place for 3 months or more, that pain is likely to be classified
as chronic. Since it lasts so long, it does not serve as a useful
warning.
Most common kinds of pain:
Head and Neck Pain
The most common origins of head and neck pain are neurogenic (nerve
root compression, peripheral neuropathy, herpetic neuralgia), soft
tissue pain (cervical strain, myofascial pain), musculoskeletal pain
(degenerative joint disease, fracture, neoplasm, degenerative disk
disease), or sympathetic pain. Depending on pain origin, there are
different treatment options.
Low Back Pain
Low back pain originates from any of four major structures: bone
(degenerative joint disease, spinal stenos, facet arthropathy,
metastatic malignancy), lumbar disk (herniated nucleus pulposus,
degenerated ruptured disk), musculoskeletal system (muscles and
ligaments strain, muscular spasm), and nerves (neuropatic pain).
One of the most difficult types of pain to treat is post-surgical
arachnoiditis (failed back surgery syndrome). Up to 85% of patients
with low back pain cannot be given a definitive diagnosis because of
the poor association among symptoms, pathologic findings and imaging
results.
Upper Back and Thoractic Pain
Although upper back pain and thoracic pain are not very common spinal
disorders, they tend to result in significant discomfort and pain.
Thoracic pain may be caused by internal organ pathology (lung cancer,
esophageal disorders, heart disorders), referral pain (cardiac angina,
cholecistitis), muscular irritation (myofascial pain), joint
dysfunction of thoracic cage and upper back, pain from herniated or
degenerated disk, nerve pain (intercostal neuralgia, herpes zoster),
pain from osteoporotic vertebra body collapse.
Abdominal Pain
Abdominal pain is usually caused by disease of internal organs of the
abdominal cavity and is treated by a gastroenterologist or surgeon.
Interventional pain management is offered to patients who suffer from
advanced cancer of internal organs (especially pancreatic cancer) or
other chronic conditions (chronic pancreatitis, abdominal angina).
Most of the time, treatment is very successful.
Chronic Pelvic Pain
Chronic pelvic pain may occur in the presence of known or suspected
organic pathology, or without any evidence of an underlying physical
cause. Pelvic pain is more common in women, with most common reasons
being endometriosis, endometritis, pelvic inflammatory disease, pelvic
adhesions, neoplasm, and myofascial pain of the pelvic floor muscles.
Pelvic pain may persist even after total hysterectomy.
Central Pain
Central pain is produced by lesions of the central nervous system:
spinal cord, brain and brainstem. An example of central pain are:
multiple sclerosis, neoplasm, patients with stroke.
Peripheral Nervous System Pain
Peripheral nervous system pain ( peripheral neuropathy) results from
peripheral nerve lesions. This peripheral nerve lesions may be caused
by Herpes Zoster (postherpetic neuropathy), diabetes (diabetic
neuropathy), entrapment neuropathy ( pain after inguinal hernia
repair), chronic alcoholism (alcoholic neuropathy).
Reflex Sympathetic Dystrophy
Reflex Sympathetic Dystrophy (RSD), or Complex Regional Pain Syndrome
(CRPS I), applies to a variety of seemingly unrelated disorders having
similar clinical feature and manifesting the sane fundamental
disturbed physiology. Causalgia or Complex Regional Pain Syndrome
(CRPS II) is a historical term describing a RSD that follows partial
or complete injury to peripheral nerve trunk. Pain is characterized by
constant, spontaneous, severe burning pain. If persistent, it results
in trophic changes.
Phantom Limb Pain
Phantom Limb Pain describes painful sensations that are perceived to
originate in the amputated portion of extremity. In addition, patient
may have localized pain following amputation, which originates from
the stump itself.