What is the problem if menstruation hasn't come for a long time?

Patient's question:

I haven't had my period for a long time

Doctor's answer:

But if there is no menstrual period for half a year, it should be considered as amenorrhea. Factors such as mental stress, excessive tension, cold stimulation, environmental changes, and malnutrition can all lead to the inhibition of central nervous system function, thereby reducing the secretion of pituitary gonadotropin and causing amenorrhea. Medical examination and treatment should be sought when necessary.