What are the nose difficulties?

Take it to the vet. When you decided to keep him/her as a pet, it became your duty to give him/her the best care possible.

Your nose runs on you, you know, nose gunk. And if you ran on your nose then you wouldn't be able to breath through it!

because they nose how to smell

Take it out and switch to a wider ring or long bar. Do warm water soaks to reduce the swelling.

If the piercing is recent, very carefully, once it is healed, you can clean it as usual.