A person is dehydration and they start to bleed from their nose. But they're bleeding from only one nostril. Why?

Dryness of the nasal mucosa.
A dry nasal mucosa causes itching and people often scratch inside the nose due to this. It damages the delicate inner lining over the nostrils. Even if one does not scratch, the capillaries present there can rupture and bleed spontaneously due to excess dryness. This happens because the nasal mucosa is very thin and fragile. In conclusion, bleeding from one nostril is caused by too much Dry air — when your nasal membranes dry out, they're more susceptible to bleeding and infections.

Bruh i don’t know the answer tbh but you can google it