Primary empty sella syndrome is thought to be congenital (present at birth) in most cases, and is caused by a failure or opening of the diaphragma sella. This may be an accidental occurrence, with no known triggering or causative factors.
you have what is known as Empty Sella Syndrome. Its not a life threatening condition but you must have your hormonal levels investigated as 10% of ESS cases are associated with hypopituitarism which would require hormonal supplementation
Secondary empty sella (acquired) may be caused by a medical procedure, such as surgery or radiation for a pituitary tumor. Disease or trauma may also reduce the size of the pituitary, or eliminate it completely.