Pain is defined as an unpleasant sensation associated with an injury1. It is a form of protective mechanism to prevent further damage to bodily tissue. Pain is subjective that can be described in terms of stabbing, burning, twisting, tearing, squeezing, and/or of a physical or emotional reaction, such as terrifying, nauseating, sickening.
Pain can be classified in numerous ways, such as the types of pain (nociceptive, neuropathic, inflammatory), by pain intensity (mild, moderate, or severe), or most commonly by duration of pain (acute or chronic pain)1. It is helpful to understand the classification of pain as it helps in guiding assessment and treatment.
Nociceptive pain occurs as a consequence of cell damage from intense pressure, swelling, and temperature, that trigger the sensory nerves, also known as the nociceptors. Electrical impulses are generated from these nerve and travel to the brain that translates to feelings of pain. Nociceptive pain is divided into either visceral (internal organs) or somatic (skin, muscle, bones, joints, and ligaments) pain.
Inflammatory pain occurs when the body shifts from preventing tissue damage to promoting of healing. This inflammatory process happens in the following sequence, from reduction of the pain threshold, to increase in pain sensitivity of the injured area, decrease in movement of the area, and promotion of healing. Maladaptive inflammation may occur and lead to shifting pain from an acute to chronic process.
Neuropathic pain results from nerve damage and is often described as burning, shooting, or sharp pain. This type of pain can be acute or chronic. Some examples of neuropathic pain are postherpetic neuralgia (complication of shingles), drug-induced peripheral neuropathy (i.e. platinum, taxanes, vinca alkaloids, etc.), and diabetic neuropathy.
Pain can be acute or chronic. Recognizing whether pain is acute or chronic is essential as treatment strategy is determined based on acute and chronic pain types. Pain can lead to signs of hypertension and tachycardia.
Acute pain is typically short in duration of less than 3-6 months. It is often nociceptive in nature, which is commonly caused by surgery, acute illness, trauma, labor, medical procedures, and cancer. Under normal circumstances, acute pain can resolve quickly as the healing process kicks in. However, it can lead to chronic pain if it is untreated or unresolved.
Chronic pain on the other hand, can persist for months to years. Chronic pain is often associated with change to nerve function and transmission, making it harder to treat. Chronic pain over time can result in physical symptoms such as fatigue and muscle tension, and psychological effects such as depression, anxiety, and anger.
Assessment helps in guiding the treatment strategy of pain1,2. Since pain ...