What does it mean when you laugh and your side hurts?

The pain you feel in the sides caused by laughing is often called a "stitch". It usually occurs with vigorous or prolonged laughter. The exact medical term for this is "transient abdominal pain" (TAP).

Causes of stitches during laughing include:

- sudden, forceful contraction of the diaphragm which supplies the largest muscles for breathing

- contraction of internal abdominal muscles

- sudden changes in abdominal pressure

- tension created when the ribs move up and down due to intense contraction of the diaphragm

- irritation to nerves around the diaphragm caused by muscle spasms

- tension along intercostal muscles between the ribs when the diaphragm contracts rapidly

- pressure on organs like the liver and spleen due to the quick movement of the diaphragm.