right side abdominal pain

you’re running. you’re in the last quarterof the marathon. you’re a beast! a champion! you’re incredible! but then, suddenly -- you feel a sharp painin your side. it seems to get worse and worse with every breath. it’s an attack of theside stitch! and now you have to stop running for a while so it goes away. but don’t worry! because you’re not alone.

right side abdominal pain, a 2000 study found that 69 percent of runnershad experienced a stitch, also known as exercise related transient abdominal pain, in the pastyear. and people who exercised in other ways, like swimming or bike riding, also reportedhaving gotten a stitch. but even though they’re so common, researchersaren’t really sure where the pain comes from.

remarkable that we don’t know these things,even about our own bodies. one possibility is that it’s all about yourdiaphragm, the dome-shaped muscle between your chest and abdomen. when your diaphragmcontracts, your lungs expand and fill with air. when your diaphragm expands, your lungsget smaller and the air is forced back out. but when you exercise, you might be overextendingthat muscle. when you’re running, for example, your footconsistently hits the pavement at the same time as you exhale -- when your diaphragmis at it’s highest and tightest -- it might strain the diaphragm, causing it to spasm. it could also be that forceful movement, likethe up-and-down motion of running, bounces

your internal organs around, straining theligaments trying to keep them from sliding around inside you. that’s a really gross thought. but the most likely explanation seems to pointto the peritoneum, a two-layered membrane that lines your abdominal wall and helps supportyour organs. now, normally, there’s fluid in betweenthe layers to make sure they don’t scrape together too much. because when they do, you end up with thatsharp pain. when you eat a large meal, your stomach pushesout on the inner layer, and when you’re

dehydrated -- like if you’ve been sweatinga lot from exercising -- there’s less fluid between the layers. the way your body’s moving around mightbump the two layers against each other, too. so how do you make the pain go away? first, just stop exercising for a bit. thepain will eventually pass -- unless it doesn’t. in which case, go see your doctor. becausei am not a doctor. and if you want to make sure it doesn’thappen again, it’s probably worth listening to your mom’s advice: wait a while aftera big meal before jumping in the pool or going out for a run.

working to strengthen your core might help,too. that should reduce the movement in your abdomen while you’re exercising, meaningless strain on your ligaments and membranes. this way, your internal organs and the stuffinside your abdominal cavity can stay right where they’re supposed to be, without causingstitches that slow you down. thanks for asking, and thanks especially toall of our patrons on patreon who keep these answers coming. if you’d like to submitquestions to be answered, or get these quick questions a few days before everyone else,go to patreon.com/scishow. and don’t forget to go to youtube.com/scishow and subscribe!