Why do Breasts Overgrow? Breast reduction surgeries are conducted because of the overgrowth of the breast. Some of the reasons are as follows: - Bad nourishment habits The hormonal balance of the body might be harmed since childhood by unbalanced, unhealthy and “fast feeding” dietary habits. The disruption of the hormonal balance might cause the breasts to overgrow at an early age. - Genetic Factors - Unbalance of weight: Sagging and growing of the breasts caused by frequent weight gain/loss - Pregnancies. Sagging caused by breast feeding and the frequent weight gain/loss during pregnancy