What Causes Nose Bleeding And Swelling In The Nostril?

I had a severe nosebleed that wouldn t stop and I went to urgent care and they got it to stop and told me to seek medical attention if it happens again. It hasn t but when it happened I frly a thick substance that felt like snot start to come out of my nose, I pushed it back in. I later in the nosebleed looked in the nostril and noticed it looked sort of swollen, in that nostril. After the nosebleed had stopped I blew out of that nostril and what initially looked like bloody snot cane out, however I m wondering if this could have actually been mucus membrane from the inside if my nose. The nostril doesnt look swollen at all now and it s been less than an hour since the noosebleed ended