Question: Where does the pain from a stich come from when you are running

Andrew Philp answered on 7 Nov 2014:

That is a great question!!!!

I personally don’t think anyone knows for certain why stitches occur and why they hurt!

My personal view (not necessarily right I should add!) is that a stitch should be thought of just like a cramp you might get in any other muscle, just in this case it occurs in the diaphragm/intercostal muscles. So when you exercise you breath deeper and at an increased rate and so the muscle around the lungs/ribcage are really active. If the demand of this response is greater than the speed of the systems supporting this activity then something has to give. So sometimes you pull or tear a muscle, or other times you get a cramp which stops you being able to exercise.

Typically we think of cramps occurring due a number of factors. It could be due to altered blood flow to the muscle, which in turn alters the amount of oxygen going to the muscle, and the ability to remove unwanted chemicals. It could also be due to reduced amounts of electrolytes (salts) which effect how the muscle can contract and relax. Probably it is combination of both of these factors. Regular exercise will train the diaphragm muscle just like any other muscle so you can cope with exercise better, whilst drinking water can maintain hydration status which should keep electrolytes high.

Again, great question! Really made me think!!!