In practice people often ask what is the difference between acute and chronic injury. Acute injury and pain are not interchangeable or necessarily correlated and the same goes for chronic injury and pain.
Generally, acute injury is an injury that occurs suddenly. This can be a sprain or strain of yourankle, whiplash from a car accident, a concussion from a blow to the head, or a contusion/bruising from hitting your leg off of the coffee table. Chronic injury is more related to an injury that occurs over a long period of time. This can be a repetitive strain to your neck from working in an office, injury to your knee from competitive running for years, or vibration injury to your hands from working with power tools or industrial drills. These injuries can be present with or without pain.
What is Pain?
Firstly, Pain is a very different entity and can be present when there is an injury or after an injury has healed. The brain can also create the sensation of pain within the body, a process called somatization. The International Association for the Study of Pain defines pain as: ‘an unpleasant sensory and emotional experience, associated with actual or potential tissue damage…’ Pain can be experienced very differently in one individual to another. Therefore, it is a very person specific process. There are three very important principles to keep in mind when trying to understand pain:
- It is an output of the brain (the brain modulates pain signals based on information coming to it, and relays it to our sensory centers where we feel it)
- It is a protective mechanism (we feel pain to tell us to stop doing something)
- The longer we experience pain in an area the more our body becomes sensitized to the pain signal therefore, the more easily we feel it (a positive feedback loop, that unfortunately isn’t very positive for us)
Acute pain is thought of as pain that lasts less than 3 months. Chronic pain is pain that persists for more than 6 months. Furthermore, pain that lasts between 3-6 months is known as subacute pain.
Acute pain is an appropriate and adaptive response to injury. It is there to protect us often and tell us not to do an activity or not to move a certain way. Think about a time you may have touched something hot, you felt pain immediately and unconsciously removed your hand. Or when you rolled your ankle and walked around with a limp because of the pain for 2 weeks. This was your body telling you to remove your had or you would get burned, or to not put all your weight on your ankle so it could heal. Acute pain is important for healing and recovery of injuries and should not be ignored or pushed through.
Chronic pain is pain that could be an inappropriate and maladaptive response. Think about that ankle injury again, lets say this time you felt the pain and were constantly aware and scared to move it, and never got the proper rehabilitation. Now 6 months later you still have pain in that area but there is no longer any acute injury to the tissues. Maybe it didn’t heal correctly? Perhaps your pain system is sensitized and still active despite a lack of injury? Or your brain is so used to thinking about it, it now feels pain which isn’t there? Maybe because you did use the affected area, the muscles have atrophied, and there is pain there from disuse?
In addition, chronic pain can be exhausting, emotionally draining, and debilitating. It is multifactorial and it is very difficult to predict who it will happen to and why. Treatment for chronic pain is often multidisciplinary in nature because it is multifactorial in nature. You may require physical rehabilitation to strengthen the correct muscles and start up the acute healing cascade again. It may require cognitive retraining or sensory desensitization because you may be afraid of certain activities that you once loved to do. Emotional support, counselling, or mindfulness training may also be necessary because there is a huge mental component to chronic pain and often those who suffer from it also suffer from depression or anxiety. medical management is also required in the form of medication, injections, or education to help decrease or manage pain levels and expectations of recovery.
Read more about Coping With Chronic Pain
Diagnosis and Treatment
Finally, if you or someone you know suffers from acute or chronic injury or pain it is very important that you get yourself assessed by properly trained and licenced medical professionals. Often acute injury will heal on its own in 7-21 days but an assessment can help you determine the extent of the injury. Both acute and chronic injury can require rehabilitation, activity modification, or lifestyle modification to help with recover.
Our multidisciplinary team at Headway Clinic are here to help you diagnose, rehabilitate, and understand your injury or pain.