An endometrial thickness of 1.6 centimeters is considered endometrial over-thickening and is more serious, so it is important to seek medical attention to find out the cause and treat it. Although the thickness of the uterine lining varies with the menstrual cycle, the normal thickness of the uterine lining is usually between 1-10 millimeters. An endometrial thickness of 1.6 centimeters is considered to be too thick, which may lead to excessive menstruation, irregular menstruation, prolonged menstruation, as well as endometritis, endometrial hyperplasia and other diseases. Women with thickened endometrium should be treated accordingly under the guidance of a doctor and should not take medication without authorization.