Estrogen imbalance has many causes, from abnormal function of the ovaries to normal processes including menopause. When the body makes an excessive amount of estrogen, method . 'excess estrogen." Symptoms of excess estrogen range from rapid, unexplained extra weight, breast tenderness, headaches, heavy periods, mood swings, and anxiety. Often, these symptoms are generated by hormone replacement therapy patients taking excessive a dose of estrogen to combat the the signs of menopause (Lee).