The breast tissue is located between the 2nd and 7th ribs in the chest area. In the inner structure of this tissue, which is covered with skin from the outside, there are glands, adipose tissue and connective tissue. 

Each breast consists of 15-20 pieces independent milk-producing units called lobes. Each lobe is divided into 20-40 pieces smaller subunits. These subunits are again divided into numerous sections in which the main milk-producing cells are collected. 

There are many milk delivery ducts and canaliculus to carry the milk produced in the breast tissue to the outside. 

Development of the Breast 

The development of the breast goes through different stages in different stages of a woman’s life. The change seen with puberty continues with pregnancy. Various changes occur at the menstruation times and with menopause. 

When Does the Breast Development Start? 

The first process of the breast development starts from the 6th week while in the mother’s womb. At the end of pregnancy, the breast nipple and the milk ducts connected to it are formed. With the adolescence period, the second change in the breast begins. With the secretion of estrogen hormone from the ovaries, the fat and support tissue increase in the breast area and the breast begins to grow. Meanwhile, the milk ducts also participate in this growth.  

Together with the woman begins to menstruate, the breast tissue develops and mammary glands form at the end of the milk ducts. The development of the breast, which begins with puberty, spectates different for every woman. In each menstrual period, the breast tissue develops a little more and this development continues until the 30s. 

What Are the Changes in the Breast During the Menstrual Period? 

The growth of the milk ducts in the breast increases with the effect of the estrogen hormone increased in the first period of menstruation. Ovulation occurs in the middle of the menstrual period with the effect of the increased estrogen hormone in this period. Following this, the increase in progesterone hormone begins; this enables the development of the mammary glands. Meanwhile, water retention in the breast increases, the breast becomes stretched and sensitive. This development in the breast is the cause of the pain and tenderness that occurs near menstruation. 

In the time close to menstruation, the externally palpable structure of the breast also changes; various mass formations can be felt in the breast with the development of the mammary glands. Therefore, ideally, self-examination should be done within the first week after menstruation. 

Changes Seen in the Breast During Pregnancy and Breastfeeding 

The full development of the breast only takes place with birth. The changes that begin in the breast are one of the earliest signs of pregnancy. As a result of the development of milk ducts and milk glands, there are complaints such as pain in the breast, pain in the nipple of the breast, and burning. The milk ducts and mammary glands develop in early pregnancy. Starting from the 5th or 6th month of pregnancy, the breasts reach the capacity to produce milk.  

Changes Seen During Menopause Period 

Together with the approach of menopause, an excessive decrease in the level of estrogen and progesterone hormones is observed. A regression begins in all tissues, including the breast, which are under the influence of estrogen hormone. There is regression in the mammary glands, the amount of water in the connective and supportive tissue decreases, its elasticity is lost and the breast sags.