What are the signs and symptoms of a broken nose?

The clinical symptoms of a broken nose after a nose trauma or accident are:  bleeding, swelling, bruising around the eyes, deformity such as a crooked nose, or flat nose, difficulty breathing and some times pain.  My advise is to go immediatly to an emergency room to be examined and have some x rays and CT scans taken and if possible having your nose taken care that same day

The most obvious sign of a broken nose is crockedness. This can be difficult to see early after the injury becase of swelling. Bruising (black eyes), a nose bleed at the time of the injury are also suggestive of a break. However, swelling can make it difficult to evaluate for a break, so it's always best to see a qualified physician to evaluate the injuryt. If you have severe pain inside the nose and blockage of nasal breathing, an injury called a septal hematoma is possible. In that case seek medical attention right away. Thanks for your question. 

Any traumatic nasal injury can cause the following:
Bleeding
Swelling
Change in the shape of your nose
Septal Haematoma (blood collection in the septum) - this needs to be dealt with urgently

I would suggest seeing an ENT/nasal surgeon as soon as this has occurred to ensure there are no acute complications that need addressing eg. Haematoma. If there is an obvious deformity, this needs to addressed within 2 weeks via a simple manipulation of the nasal bones. Any longer and you will require a formal rhino/septorhinoplasty.