Gus Mantia, M.D.

Pain - a definition

Pain is a very common complaint. It is secondary only to upper respiratory infections as the reason why people seek medical care. Obviously, effective treatment of pain will lessen suffering and improve the quality of one’s life.

The International Association for the Study of Pain defined "Pain" as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. I think a less wordy definition of Pain is an "unpleasant sensation." Pain "is" what ever a patient says it is. What is important to realize is that sometimes what is painful to one person may not be to another.

Some people believe that as people get older, they become less sensitive to pain, and therefore do not feel pain. This is absolutely false ! Some people believe that chronic pain is to be expected as one gets older. This is absolutely false! Some people believe that they should not tell people that they are in pain. This is absolutely incorrect. How can anybody seek help or treatment if they are unwilling to express their discomfort to others.

Pain can be divided into two classifications: Acute and Chronic. Acute pain is usually secondary to an illness or injury that is or has caused tissue damage. But, the main point is that most often this pain is self limited, and will resolve in days or weeks once the medical problem is corrected or has healed. Examples of acute pain would include bruises, bone fractures, infections, heart attacks, muscle sprain/strain, arthritis (gout), etc.

Chronic Pain - a definition

Chronic pain, on the other hand , can continue on for years after the problem has resolved or the illness has healed. Chronic pain can develop following an acute pain event, but it may also start on its own and gradually increase in severity over time. Unlike acute pain which indicates there is ongoing tissue damage or repair, chronic pain does not indicate there is ongoing tissue injury or destruction. Examples include: arthritis, muscular pain, old bone fractures, shingles (injured nerves), etc. Chronic pain can result in anxiety, fear, depression, and helplessness. Chronic pain can diminish a person’s activity, appetite, and sleep. Pain management treats the physical, psychological, and emotional suffering of not only the patient, but also of their whole family and care givers. The goal is to relieve as much pain as possible to enable the patient to enjoy life to the fullest and/or their satisfaction.

Before blindly treating acute or chronic pain, it is best to determine the etiology of the pain, and determine if any medical intervention is indicated towards the disease/injury, of which would hopefully result in pain relief. Again, it must be certain that the pain is not coming from vital organs such as the heart, stomach, kidney, aorta, etc. Examples of some serious problems that can present as back pain include stomach ulcers, kidney problems, aneurysms. Arm or leg pain can be secondary to ischemia (lack of blood, blocked arteries) or thrombophlebitis (blood clots).

Before I start talking about chronic pain, I would like to discuss how the body "feels" pain. Pain is perceived through complex pathways leading from our skin and other body areas to our brain. Many different chemicals and electrical signals modulate (affect) each other at multiple sites before the impulses reach our brain.

There are two basic types of pain, nociceptive and neuropathic.

Nociceptive pain is produced through the stimulation of nerve receptors in our skin, muscle, fascia, and organs. The pain signal is produced by the nerve receptor usually responding to potential or true tissue damage, and the electrical signal then travels to the spinal cord where it interacts with other electrical signals coming into the spinal cord. Then, the signal is sent up to the brain where we perceive the pain. If the pain signal can be blocked before it reaches the brain, the pain will not be perceived or felt. Examples of nociceptive pain include broken bones, muscular pain, internal organ pain, arthritis, and headaches. Common pain sensations include aching, throbbing, soreness, sharp, and stabbing. Medications such as NSAID’s (Non-Steroidal Anti-inflammatory Drugs) and opioids are usually effective for controlling this type of pain.

Neuropathic pain can occur following a nerve injury or irritation, such as with shingles, amputations, multiple sclerosis, spinal cord injury, pinched nerves, etc. Neuropathic pain involves the spontaneous production of abnormal pain electrical impulses without an appropriate stimulus to the nerve receptor, that leads to the perception of pain. In other words, pain impulses start spontaneously in the middle of damaged nerves, and the pain signals then progress to the brain. Common pain sensations include burning, extreme sensitivity, lancinating, and electric shock type sensations. Regarding treatment, NSAID’s are sometimes effective for neuropathic pain secondary to an inflammatory process, but most often they are not effective. Opioids are effective some of the time. Adjuvant medications such as tricyclic anti-depressants and anti-convulsants can be very effective for neuropathic pain, but sometimes no medications help adequately.

The important point of understanding how pain is perceived is that there are many different steps where pain pathways may be blocked or affected in order to decrease perceived pain. This is the theory for using multi-drug therapy for the treatment of pain, as different medications interrupt pain pathways at different steps. Often, pain can be treated more effectively by a combination of medications than by using any single medication.

The first step to treating pain is to diagnose the pain, and its etiology. This is accomplished in a similar fashion as with all new medical problems. A detailed pain history is obtained as to the onset, location, quality (what the pain feels like), exacerbating, and relieving factors of the pain. A pertinent physical exam is performed looking for anatomical and neurological abnormalities. Sometimes, reproduction of the pain during the physical exam can be very informative. A presumptive pain diagnosis(s) can be made and various studies can be ordered if indicated. Pain treatment can be instituted at this time, before a final diagnosis is reached.