The septum starts out in life straight and in the middle. In the normal course of life, the septum can get injured and become deviated. A hit in the nose from a baseball, a fall off a bike, a punch, a kick, or an elbow to the face while playing basketball can all cause the septum to become deviated. An injury is usually the cause of deviation of the septum. The injuries may become forgotten from childhood or may not have even been severe. Rarely, the septum can become deviated during childbirth.
A deviated septum may or may not be responsible for the blocking the breathing of the nose, and it may only be partly responsible. It is up to your doctor to decide if it is blocking breathing or partly blocking your breathing or not. It can be fixed. Surgery (called a septoplasty) is the only way to fix it. Medicines cannot repair deviated cartilage or bone.