What is visceral pain?
Pain in your abdomen due to appendicitis is known as visceral pain, because it is caused by inflammation of an internal organ, in this case the intestines. It can also occur in other internal organs, such as the liver, stomach and lungs.
The inflammation causes damage to the tissues. The damaged tissues release all kinds of substances that activate tiny receptors at the ends of the nerves in the internal organs, called nociceptors. The activated receptors send signals (electrical impulses) through the nerves to the spinal cord. From there, they are passed on to the brain, giving you a sensation of pain.
Visceral pain can be nociceptive pain, the type of pain you feel when you sprain your ankle, but it is not as easy to localise as in the case of a sprained ankle. Visceral pain is described as pain affecting a larger area (diffuse pain), for example, the lower abdomen, the left half of the abdomen, etc.