eli5: When my nose starts bleeding and I pinch it to stop the blood, where does all the blocked up blood go?



When I get a nosebleed I immediately pinch my nostrils closed and after about 3 minutes I let go and the bleeding has stopped and there is no blood piled up in my nostril? Where has the blood gone?

In: Biology

The blood fills your sinuses then drips down your throat.

This is why it’s recommended to lean forward. If you have clothing problems it can be serious.

Two possibilities:

1. You have successfully pinched off the blood vessel to prevent further bleeding (the pressure you create is greater than the pressure driving blood out of the vessel) or at least has greatly slowed down the bleeding. This allowed for clotting factors/platelets to close the hole that the bleeding came from.
2. The blood has now flowed down the back of your nasal cavity and drips down your throat. The reason that the bleed has stopped is simply that enough time has elapsed that a clot has sealed off the blood vessel tear.

You squeeze the tiny blood vessels shut, which keeps them from leaking. It lets the blood in the area sit still long enough to form little tiny clots, which lets the bleed stop. Imagine a water hose out in the freezing temps. It won’t freeze shut easily if it’s running. But if you kink it shut for a while, the end of it can freeze over.