What is the difference between acute and chronic pain?

It is base on time: One classification: acute pain if less than a month, sub-acute if between 1-6 months, and chronic as more than 6 months since the time of onset. Others may classify as less than 3months, 3-6 months, and more than 6 months. Lets not to forget that patient might have acute exacerbation of chronic pain.

Duration: Acute and chronic pain are differentiated by the duration of the pain symptoms themselves. Acute pain is often very quick in onset but also relatively rapid in dissipating, ie. Less than a few weeks. Whereas chronic pain can be both slow and quick in onset, however its duration can be quite lengthy, ie. 2-3 months or more in duration and sometimes unfortunately many years.

How long pain lasts: Acute means rapid onset of pain, and is usually relatively quick to resolve. An example would be pain from a minor scrape or burn. Chronic means long term pain, such as seen with arthritis or major sports injury.

Duration: The duration of pain determines if it is acute or chronic.

Duration: Acute pain lasts an order of days or weeks, while chronic pain can last months to years or even be permanent. They typically have different causes.

Duration of pain: Acute pain is a pain that has not lasted more than it is expected to last for the condition that produced this pain. Chronic pain is that has lasted longer than expected. Any pain that has lasted more than 3 months in most cases would be considered chronic.