What Is Visceral Pain?

Visceral Pain Is Pain From Internal Organs

Senior patient suffering from backache
BJI / Blue Jean Images/Getty Images

Visceral pain is a type of nociceptive pain that comes from the internal organs. As with somatic pain, pain receptors called nociceptors send signals to the spinal cord and brain when damage is detected. Unlike somatic pain, however, visceral pain is harder to pinpoint.

Some types of pelvic pain, such as those caused by irritable bowel syndrome or bladder disorders, are considered to be visceral pain.

Other ways somatic pain and visceral pain are different.

Visceral pain is often described as generalized aching or squeezing. It is caused by compression in and around the organs, or by stretching of the abdominal cavity. Sometimes visceral pain may radiate to other areas in the body, making it even harder to pinpoint its exact location.

Visceral pain responds well to weak opioids such as codeine, though stronger opiods such as morphine may also be used.

The Difference Between Superficial and Deep or Visceral Pain

When you cut yourself on a knife, you experience sharp and rapid pain. This pain is superficial in nature. Deeper organs lack receptors that convey sharp and rapid pain thus the quality of this deep pain or visceral pain is different from superficial pain.

Furthermore, when you cut your finger, you know where the pain is; you're able to localize it. With deeper and visceral pain, it's harder to tell exactly where the source of the pain is.

Thus, more systemic, or system-wide symptoms, typically accompany visceral pain, such as nausea, sweating and changes in blood pressure. Moreover, visceral pain can set off muscle spasms. Finally unlike superficial pain, visceral pain tends to radiate to other body parts making the whole pain experience more diffuse and markedly unpleasant.

Overall, the pain receptors present in the viscera or internal organs are similar to those found on the skin. However, these pain visceral receptors are more sparsely distributed and exhibit fewer numbers of proprioceptors as well as touch and temperature receptors. Of note, proprioceptors relay information to your brain about joint angle, muscle tension and muscle length, which help with body positioning.

Simulating Visceral Pain in the Lab

In a curious experiment, researchers have attached a balloon to a tube and then inflated this balloon while in the stomach. Researchers were thus able to better appreciate the severe nature of this visceral pain and found that its greatest with organ distension.

For example, if you have small bowel obstruction, the intestines distend and cause intestinal colic. Colic waxes and wanes. Furthermore, distension leads to inflammation and organ injury, which is especially sensitive to even the most minor stimuli such as movement. If you've ever seen a person with bowel obstruction, you know that even the most subtle movements can bring on severe pain.

Selected Sources

Barrett KE, Barman SM, Boitano S, Brooks HL. Somatosensory Neurotransmission: Touch, Pain, & Temperature. In: Barrett KE, Barman SM, Boitano S, Brooks HL. eds. Ganong’s Review of Medical Physiology, 25e. New York, NY: McGraw-Hill; 2016. Accessed January 26, 2016

Continue Reading