High level of stress, dramatic changes in your life style, high cholesterol, hormonal imbalance as seen in thyroid problems and PCOS, chain smoking, may be some of the common causes of your
irregular periods. Cushing’s disease
and disorders of adrenal gland, tumors of the ovaries and adrenals, insulin resistance and obesity are some of the other factors. Prolonged use of oral contraceptive pills is another cause. Other important local causes of irregular periods are PCOS and fibroid uterus.