What is the difference between “small breast causes” and “sagging breast causes”?  
The breasts are specialized organs, which are located on the anterior chest wall. The breast consists of: Milk glands (lobules), special ducts (Extralobular ducts) that transfer milk from the lobules to the nipple, Nipples, Areola (the pink/brown pigmented region surrounding the nipple), breast ligaments, Breast muscle (Pectoralis muscle), and Fat Tissue. Small breasts and sagging breasts are conditions that might result you in having a lack of confidence. What is the difference between small breasts and sagging breasts?

Small breasts women
Too little breast fat tissue is usually the cause of small breast.

Sagging breasts women
Excessive function of the breast muscle usually lead to sagging breasts, which can feel very soft with conditions of being flat-chested or having a small breast base and sagging breast skin.