Causes of secondary amenorrhea include stress
and anxiety, malnutrition, depression, overexercising, sudden weight loss or gain (obesity),
thyroid disorders and hormonal imbalance due to polycystic ovarian syndrome(PCOS).Smoking is also associated with secondary amenorrhea. Sometimes tumors of the ovaries and brain may also cause absence of menstruation.
Some of these causes are modifiable like if you are having stress then yoga and meditation and antianxiety medicines can help you out.