If your nose is deformed looking as in crooked, bent or has any type of bump in it after it has been hit then it is likely broken. Also if you have had an injury and your nose is sore, bleeds or becomes bruised then you should see a doctor because your nose is likely broken. Actually what gets broken in your nose is cartilage, because your nose is made up of cartilage. If you have any of these symptoms then you need to see a doctor, because swelling and deformities of the nose can cause the air ways to become compromised.