What Is the Difference Between Acute and Chronic Pain?

Acute pain is signaled through peripheral pain receptors at an anatomic site.  As the site undergoes healing, the nociceptive receptors receive less stimulation, and activity decreases back to preinjury levels.  Chronic pain often begins with the same nociceptive signals, but prolonged signaling results in changes to the nervous system.  Neurons become hyperexcitable, and signals to the thalamus and cerebral cortex (where pain processing occurs) become amplified.¹  In addition, emotional and psychological changes that take place also color the pain experience.¹  The brain receives continued pain signals, even when there is no further tissue damage.  This concept is at the core of what differentiates acute and chronic pain: when chronic, pain does not mean ongoing tissue damage.

How Is Pain Typically Treated?

Conventional treatments of pain include ice, medications, interventional treatments, and sometimes surgery.  Analgesic medications include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol, and opioids.  Adjunctive medications include tricyclic antidepressants and anticonvulsants.  Collectively, these medications certainly have a role in treatment, but are limited in therapeutic success and have plentiful side effects.

What Are Some Non-Drug Treatments of Chronic Pain?

There are several classes of treatments other than pharmaceuticals that have the potential to help in pain.  Exercise, nutrition, supplements, mind-body techniques, and modalities such as acupuncture and spinal manipulation all have evidence of benefit in pain disorders.

Does Exercise Help Chronic Pain?

Exercise can affect pain on multiple physiologic levels, making it an ideal treatment modality.  Exercise can improve aerobic capacity, strength, and flexibility.  This combination can lead to increased functional capacity over time.  Exercise itself can alter pain perception, inducing hypoalgesia to new pain stimuli following both aerobic and strength training.²  In individuals with chronic pain, this is best demonstrated at low- to moderate-intensity training.²  Exercise is also known to have effects centrally, improving sleep and depressive symptoms.³  These symptoms commonly coexist with chronic pain and impact pain perception, making them excellent targets for treatment.