What is pain?

Mihaela B. Taylor, MD
Pain is a sensation of physical suffering. It can range from mild to excruciating, depending on how the brain processes the stimulation that is causing the pain. Each person's perception of pain is different. Pain can be either acute or chronic. Acute pain is the body's immediate response when it is injured in some way. Chronic pain is pain that has lasted for some time.
The International Association For the Study of Pain (ASP) defines pain as follows: "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage." This definition explicitly affirms that pain has both a sensory and an affective-evaluative component, and furthermore acknowledges that it may occur in the absence of obvious visceral or peripheral pathology. To fully understand chronic pain, one must integrate the sensory and affective/evaluative elements of the pain experience. It is equally misguided to focus on the psychological aspects of pain, as it is to address only the sensory component and ignore the affective dimensions.
Pain is a feeling of discomfort. Every person feels pain differently, and the amount of pain that each person can withstand varies a great deal. Depending on the cause, pain can be pointed or dull, or throbbing or steady. It can be present all the time, or it can come and go. Pain can range in intensity from mild to unbearable, and in some cases, it may be difficult to describe. Pain is the number one reason for doctor's visits.
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage is known as pain.
It is useful to distinguish between the two basic types of pain, acute and chronic, and they differ greatly.
Acute pain, for the most part, results from a disease, inflammation, or an injury to tissues. This type of pain generally comes on suddenly?for example, after trauma or surgery?and may be accompanied by anxiety or emotional distress. The cause of acute pain can usually be diagnosed and treated, and the pain is self-limiting, that is, it is confined to a given period of time and severity. In some rare instances, pain can become chronic. Chronic pain is widely believed to represent a disease itself. It can be made much worse by environmental and psychological factors. Chronic pain persists over a longer period than acute pain and is resistant to most medical treatments. It can, and often does, cause severe problems for patients.
This answer is based on source information from National Institute of Neurological Disorders and Stroke.
Eric Olsen
The word pain comes from the Latin peona, which, rather freely translated, means "punishment." (We're using the word pain rather loosely to include all the vague sensations, discomforts, and twinges that some wouldn't call pain at all, as well as the unmistakable, teeth-gritting, eye-scrunching aches we all agree is pain.) In many cases, when we don't pay attention to our pain, it can certainly become punishment. To remain unhurt so you can get all the benefits of an active life, you need to listen to your pain, become a connoisseur of pain, as it were, and understand the differences between the types of pains you may feel before, during, and after a workout. You need to know what the pains are "telling" you, which pains warn of damage and which are simply the residue of fatigue, and then respond appropriately.

In the strict clinical sense, pain is what we feel when certain specialized receptors in the skin, muscles, and other tissues are stimulated. Different receptors respond to different types of stimuli -- there are heat receptors, cold receptors, pressure receptors, "chemoreceptors," and so on -- and the intensity of the feeling, whether pain or otherwise, depends on how many of these receptors are stimulated and how frequently.

But it's all much more complicated than that. We actually feel pain only after the pain receptors send their messages to the brain, where the information is processed and interpreted. How we interpret a sensation -- as pain or a nagging "not quite pain" or even pleasure -- depends very much on our mental landscape. Pain is really a complex of physical and emotional reactions, and the two can never be entirely separated.
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.