Difficulty Breathing and Facial Pain
When septal deformities are significant, they would obstruct one or both nostrils. This obstruction or blockage would make it more challenging to breathe through your nostril. Indeed, difficulty breathing is often one of the most noticeable and earliest signs of a deviated septum. It is more obvious when you have allergies or a cold, which causes the nasal passages to narrow and swell. 
It is still debated whether a deviated septum can be a possible cause of facial pain. A possible theory is that a serious deviated septum with surfaces in the nose touching could cause pressure and lead to one-sided facial pain. However, this symptom does not always suggest an off-center nasal septum. In some cases when a deviation affects the inside wall of the nasals, you would feel pain on the face’s side in the narrowed nostril. It is important to consult your doctor as soon as possible. A simple surgical procedure would help resolve the problem. You can also take some OTC medications to alleviate the pain when the deviation is mild.