What is Pain? What causes pain? This post comes from
http://www.medicalnewstoday.com/articles/145750.php and is a great way to look at describing pain to a doctor or others. If you're like me, sometimes it is difficult to describe the type of pain that you are having. People without a chronic condition may be wondering what I mean by that statement, but it's true.
When seeing a doctor, especially for something new, I try to explain only the new symptoms that I am having.
"Yes, doctor, I have pain there, but it is not the same pain that I usually have."
Other times, it may be difficult to try to describe the pain in words. It's difficult to try to write about it because often it cannot be adequately described. Yes, I know that that sounds strange.
Anyway, here is the article...
The English word 'pain' probably comes from Old French (peine), Latin
(poena - meaning punishment pain), or Ancient Greek (poine - a word more
related to penalty), or a combination of all three.
In medicine pain relates to a sensation that hurts. If you feel pain it
hurts, you feel discomfort, distress and perhaps agony, depending on the
severity of it. Pain can be steady and constant, in which case it may
be an ache. It might be a throbbing pain - a pulsating pain. The pain
could have a pinching sensation, or a stabbing one.
Only the person who is experiencing the pain can describe it properly. Pain is a very individual experience.
Types of pain
Acute pain - this can be intense and short-lived, in which case
we call it acute pain. Acute pain may be an indication of an injury.
When the injury heals the pain usually goes away.
Chronic pain - this sensation lasts much longer than acute pain. Chronic pain can be mild or intense (severe).
How do we classify pain?
Pain can be nociceptive, non-nociveptive, somatic, visceral, neuropathic, or sympathetic. Look at the table below.
| Pain |
| Nociceptive | Non-Nociceptive |
| Somatic | Visceral | Neuropathic | Sympathetic |
Nociceptive Pain - specific pain receptors are stimulated. These
receptors sense temperature (hot/cold), vibration, stretch, and
chemicals released from damaged cells.
Somatic Pain - a type of nociceptive pain. Pain felt on the
skin, muscle, joints, bones and ligaments is called somatic pain. The
term musculo-skeletal pain means somatic pain. The pain receptors are
sensitive to temperature (hot/cold), vibration, and stretch (in the
muscles). They are also sensitive to
inflammation,
as would happen if you cut yourself, sprain something that causes
tissue damage. Pain as a result of lack of oxygen, as in ischemic muscle
cramps, are a type of nociceptive pain. Somatic pain is generally sharp
and well localized - if you touch it or move the affected area the
pain will worsen.
Visceral Pain - a type of nociceptive pain. It is felt in the
internal organs and main body cavities. The cavities are divided into
the thorax (lungs and heart), abdomen (bowels, spleen, liver and
kidneys), and the pelvis (ovaries, bladder, and the womb). The pain
receptors - nociceptors - sense inflammation, stretch and ischemia
(oxygen starvation).
Visceral pain is more difficult to localize than somatic pain. The
sensation is more likely to be a vague deep ache. Colicky and cramping
sensations are generally types of visceral pain. Visceral pain commonly
refers to some type of
back pain - pelvic pain generally refers to the lower back, abdominal pain to the mid-back, and thoracic pain to the upper back
(see below for the meaning of referred pain).
Nerve Pain or Neuropathic Pain
Nerve pain is also known as neuropathic pain. It is a type of
non-nociceptive pain. It comes from within the nervous system itself.
People often refer to it as pinched nerve, or trapped nerve. The pain
can originate from the nerves between the tissues and the spinal cord
(peripheral nervous system) and the nerves between the spinal cord and
the brain (central nervous system, or CNS).
Neuropathic pain can be caused by nerve degeneration, as might be the case in a
stroke,
multiple-sclerosis, or oxygen starvation. It could be due to a trapped
nerve, meaning there is pressure on the nerve. A torn or
slipped disc will cause nerve inflammation, which will trigger neuropathic pain. Nerve infection, such as
shingles, can also cause neuropathic pain.
Pain that comes from the nervous system is called non-nociceptive
because there are no specific pain receptors. Nociceptive in this text
means responding to pain. When a nerve is injured it becomes unstable
and its signaling system becomes muddled and haphazard. The brain
interprets these abnormal signals as pain. This randomness can also
cause other sensations, such as numbness, pins and needles, tingling,
and hypersensitivity to temperature, vibration and touch. The pain can
sometimes be unpredictable because of this.
Sympathetic Pain
The sympathetic nervous system controls our blood flow to our skin and
muscles, perspiration (sweating) by the skin, and how quickly the
peripheral nervous system works.
Sympathetic pain occurs generally after a
fracture
or a soft tissue injury of the limbs. This pain is non-nociceptive -
there are no specific pain receptors. As with neuropathic pain, the
nerve is injured, becomes unstable and fires off random, chaotic,
abnormal signals to the brain, which interprets them as pain.
Generally with this kind of pain the skin and the area around the injury
become extremely sensitive. The pain often becomes so intense that the
sufferer daren't use the affected arm or leg. Lack of limb use after a
time can cause other problems, such as muscle wasting,
osteoporosis, and stiffness in the joints.
What is referred pain?
Also known as reflective pain. When pain is felt either next to, or at a
distance from the origin of an injury it is called referred pain. For
example, when a person has a
heart attack,
even though the affected area is the heart, the pain is sometimes felt
around the shoulders, back and neck, rather than in the chest. We have
known about referred pain for centuries, but we still do not know its
origins and what causes it.
How do you measure pain?
It is virtually impossible to measure a person's pain objectively. Most
experts say that the best way to find out how much pain a person is
enduring is by a subjective pain report. A comprehensive assessment of
pain should include:
- The identification of all the pains. This must include the most important ones.
- The site, quality, and radiation of pain
- What factors aggravate and relieve the pain
- When the pain occurs throughout the day
- What impact the pain has on the person's function
- What impact the pain has on the person's mood
- The sufferers' understanding of their pain
There are many different methods for measuring pain and its severity.
Health care professionals say it is important to stick to whatever
system or tool you chose for a specific patient all the way through. If a
patient is unable to report his pain, such as an infant, or a person
with
dementia, there are a number of observational pain measures a doctor can use.
Here is a list of some pain measures used today:
Numerical Rating Scales
The patient is given a form which asks him to tick from 0 to 10 what his
level of pain is. 0 is no pain, 5 is moderate pain, and 10 is the worst
pain imaginable.
| Please rate the pain you have right now |
| 0 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| No pain | | | | Moderate pain | | | | | Worst pain imaginable |
The Numerical Rating Scales are useful if you want to measure any
changes in pain, as well as gauging the patient's response to pain
treatment. If the patient has
dyslexia,
autism, or is very elderly and has dementia this may not be the best tool
(see the ones below).
Verbal Descriptor Scale
This type of scale exists in many different forms. The patient is asked
questions and responds verbally choosing from such terms as mild,
moderate, severe, no pain, mild pain, discomforting, distressing,
horrible, and excruciating.
Elderly patients with cognitive impairment, very young children, and
people who respond better to verbal stimuli tend to have better
completion rates with this type of scale, compared to the written
numerical scale. Children respond even better to the faces scale
(description below).
Faces Scale
The patient sees a series of faces. The first one is calm and happy, the
second less so, etc., and the final one has an expression of extreme
pain. This scale is used mainly for children, but can also be used with
elderly patients with cognitive impairment. Patients with autism may
respond better to this type of approach - people with autism tend to
respond to visual stimuli well.
Brief Pain Inventory
This is a much more comprehensive written questionnaire. Not only does
it gauge current level of pain, but also records the peaks and troughs
of pain during previous days, how pain has affected mood, activity,
sleep patterns, and how the pain may have affected the patient's
interpersonal relationship. The questionnaire also has diagrams which
the patient shades - the shaded parts being where the pain is located
and where it is most severe.
McGill Pain Questionnaire
This questionnaire measures the intensity (severity) of the pain, the
quality of the pain, mood, and understanding of the pain. It is also
known as the McGill Pain Index. It is a scale of rating pain developed
at McGill University by Melzack and Torgerson (1971).
Look at the 20 groups below.
- Circle one word in each group that best describes your pain.
- Circle only three words from Groups 1 to 10 that best describe your pain response.
- Choose just two words in Groups 11 to 15 that best describe your pain.
- Just pick the one in Group 16.
- Finally, choose just one word from Groups 17-20.
You should now have seven words. Those seven words should be taken to
your doctor. They will help describe both the quality and intensity of
your pain.
Group 1 - Flickering, Pulsing, Quivering, Throbbing, Beating, Pounding
Group 2 - Jumping, Flashing, Shooting
Group 3 - Pricking, Boring, Drilling, Stabbing
Group 4 - Sharp, Gritting, Lacerating
Group 5 - Pinching, Pressing, Gnawing, Cramping, Crushing
Group 6 - Tugging, Pulling, Wrenching
Group 7 - Hot, Burning, Scalding, Searing
Group 8 - Tingling, Itching, Smarting, Stinging
Group 9 - Dull, Sore, Hurting, Aching, Heavy
Group 10 - Tender, Taunt, Rasping, Splitting
Group 11 - Tiring, Exhausting
Group 12 - Sickening, Suffocating
Group 13 - Fearful, Frightful, Terrifying
Group 14 - Punishing, Grueling, Cruel, Vicious, Killing
Group 15 - Wretched, Binding
Group 16 - Annoying, Troublesome, Miserable, Intense, Unbearable
Group 17 - Spreading, Radiating, Penetrating, Piercing
Group 18 - Tight, Numb, Squeezing, Drawing, Tearing
Group 19 - Cool, Cold, Freezing
Group 20 - Nagging, Nauseating, Agonizing, Dreadful, Torturing
Measuring pain when the patient is cognitively impaired
In this case doctors say that the patient's subjective pain report is
the most effective and accurate way of evaluating pain. If the severely
cognitively impaired patient is observed carefully it is possible to
pick out clues as to the presence of pain, e.g. restlessness, crying,
moaning, groaning, grimacing, resistance to care, reduced social
interactions, increased wandering, not eating, and sleeping problems.
What are the treatments for pain?
An underlying disorder, if treated effectively, will also get rid of the
pain, or at least reduce it. If you have an infection and take
antibiotics,
the antibiotics may get rid of that infection, resulting also in the
elimination of pain. Even if an underlying problem can be treated, you
may still need analgesics (pain relievers).
Analgesics are good at relieving nociceptive pain, but not neuropathic
pain. Chronic pain - long-lasting pain - may need other non-drug
treatments as well.
Opioid Analgesics
Opioid analgesics are also known as narcotics. These are the strongest painkillers and are commonly used after surgery, for
cancer,
broken bones, burns, and various other situations. Even though opioids
are not commonly used to treat non-cancer pain, their usage for
non-cancer pain is becoming more widespread and acceptable. Some
patients do not respond well to opioids and should not take them.
The patient will be given opioids in gradually increasing dosages. The
ideal dose is reached when the pain is relieved and the side-effects are
tolerable (increase any higher and the side effects become too much for
the patient). Dosages should be generally much lower for older patients
and infants.
The patient is administered opioids every few hours - each dose
coinciding with the moment just before the pain starts becoming severe.
Some patients are given higher dosages if the pain becomes more intense,
while others are given other medications alongside the opioid. Pain can
become more intense if the patient needs to move about, or if a wound
dressing needs to be changed.
The dosage goes down if the pain intensity drops, until if possible, the doctor switches to a non-opioid analgesic.
People with kidney failure, liver problems, COPD (chronic obstructive
pulmonary disease, dementia, tend to have more side effects when given
opioids. The most common opioid side effects are drowsiness,
constipation,
nausea, vomiting, and itching. Generally, the side effects lessen as
after time. Taking too much opioid can be dangerous. Patients who take
opioids for long period become physically dependent and will have
withdrawal symptoms when treatment is stopped - it is important that
their dosage is tapered off gradually.
Nonopioid Analgesics
Nonopioid analgesics are used generally for mild to moderate pain. They
are not addictive and their pain-relieving effects do not dwindle over
time.
NSAIDs (nonsteroidal anti-inflammatory drugs)
These may be obtained either OTC (over-the-counter) or as a prescription medication, it depends on the dosage. Low dosage
NSAIDs are effective for
headaches, muscle aches,
fever,
and minor pains. At a higher dose they help reduce joint inflammation.
There are three main types of NSAIDs, and they all block prostaglandins -
hormone-like substances that cause pain, inflammation, muscle cramps,
and fever.
- Traditional NSAIDs - the largest subset of NSAIDs. As is the case with most drugs, they do carry a risk of side-effects, such as stomach upset
and gastrointestinal bleeding. The risk of side effects is
significantly higher if the patient is over 60. At higher doses, they
should only be taken when monitored by a doctor.
- COX-2 inhibitors - these also reduce pain and inflammation.
However, they are designed to have fewer stomach and gastrointestinal
side-effects. In 22004/2005 Vioxx and Bextra
were withdrawn from the market after major studies showed Vioxx carried
increased cardiovascular risks, while Bextra triggered serious skin
reactions. Some other COX-2 inhibitors are also being investigated for
side-effects. The FDA told makers of NSAIDs to highlight warnings on
their labels in a black box.
- Salicylates - these include aspirin
which continues to be a popular medication for many doctors and
patients. If your plan to take aspirin more than just occasionally you
should consult your doctor. Long term high dosage usage of aspirin
carries with it a significant risk of serious undesirable side effects,
such as kidney problems and gastrointestinal bleeding. For effective
control of arthritis
pain and inflammation frequent large doses are needed. Nonacetylated
salicylate is designed to have fewer side effects than aspirin. Some
doctors may prescribe nonacetylated salicylate if they feel aspirin is
too risky for their patient. Nonacetylated salicylate does not have the
chemical aspirin has which protects against cardiovascular disease. Some
doctors prescribe low dose aspirin along with nonacetylated salicylate
for patients who they feel need cardiovascular protection.