brain, spinal cord, and nerve disorders
Overview of Pain
Acute versus chronic pain
Pain may be acute or chronic. Acute pain means pain that begins suddenly and does not last long (days or weeks). Chronic Pain lasts for many months or years. When severe, acute pain may cause anxiety, a rapid heart rate, an increased breathing rate, elevated blood pressure, sweating, and dilated pupils. Usually, chronic pain does not have these effects, but it may result in other problems, such as depression, disturbed sleep, decreased energy, a poor appetite, weight loss, decreased sex drive, and loss of interest in activities. 