Can you explain the difference between acute and chronic pain, writes MARION KERR
Pain may be classified as acute or chronic. Acute pain begins suddenly and usually does not last long. Severe, acute pain can cause anxiety, a rapid heart rate, an increased breathing rate, elevated blood pressure, sweating and dilated pupils.
Chronic pain lasts for weeks, month or even years and may recur. It tends to last longer than expected based on the illness or injury. It can be associated with a chronic disorder (such as cancer, arthritis, diabetes or fibromyalgia) or an injury that does not heal.
Chronic pain may result in a range of problems, including sleep disturbances, depression, decreased energy levels, poor appetite, weight loss, loss of libido and reduced interest in activities.
I am prescribed high doses of painkillers for a chronic back problem. But even with these I occasionally experience severe episodes of pain. Why does this happen?
During treatment, many people experience a brief, sometimes severe, flare-up of pain. It is called breakthrough pain because it breaks through in spite of regular pain treatment. Typically, breakthrough pain begins suddenly, lasts up to an hour, and feels much like the original chronic pain except it is more severe. It may differ from person to person and is often unpredictable.
Does chronic pain change the way you feel pain?
Yes, this type of pain can make the nervous system more sensitive to pain. Chronic pain repeatedly stimulates the nerve fibres and cells that detect, transmit and receive pain signals. Repeated stimulation can change the structure of nerve fibres and cells.
It can make them more active and this, in turn, can increase pain transmission to the spinal cord and brain. As a result, pain may result from stimulation that might not ordinarily be painful. It can also make painful stimuli feel more severe.
When pain occurs, the body may anticipate it by becoming anxious and afraid. Such emotions can stimulate the production of substances that make pain feel more intense.
Fear and anxiety can also reduce the production of substances called endorphins. These are natural pain killers which reduce the sensitivity of nerve cells to pain. And fatigue can also affect how we perceive pain.
Changes in pain sensitivity may in some way account for pain that persists after its cause has resolved. It may also explain why, for some, pain can feel more severe than expected.
