Why does breast size differ?
The size, and even the shape, of two parts of the body are usually not the same. The same applies to the breasts in women. However, the difference is so slight that most people will not notice it. Sometimes it is significant enough to be visible to a person, and even to others, yet it is nothing to worry about. However, if there is a gross enlargement of one breast compared to the other, especially if it has arisen suddenly, then it needs to be investigated further by a medical professional.
There are several reasons for one sided breast swelling. There is no need to panic immediately if there is a slight difference that has arisen almost overnight. The changes during the course of your menstrual cycle can contribute to changes in your breast size and sometimes one breast may seen to be more affected than the other. All too often, it is the perception of the individual and there is actually no abnormality. Nevertheless it does not harm to see a doctor and get a professional opinion on the matter.
Reasons for Changes in Breast Size
Apart from the alterations of hormone levels as part of a menstrual cycle, pregnancy, breastfeeding and menopause, there are several other reasons that should be considered if you are concerned about the change in size of one breast from the other. Changes in size of one breast from the other is more common in young girls and women using oral contraceptives or hormone replacement therapy (HRT). It is considered normal in these instances.
However, sometimes the enlargement in one breast is due to swelling, a cyst, an abscess, a tumor or even implants. It is these cases that are a cause for concern. Pain is not always a definitive symptom of a breast problem and neither is enlargement. Further medical examinations like a mammogram may therefore be necessary in order to identify the exact cause. Usually a hormonal condition leads to enlargement of both breasts simultaneously although one breast may be more reactive to the hormones than the other breast.
Conditions Where One Breast Is Larger
Breast tumors are often the concern for most women. However, not every tumor is malignant (cancerous). Tumors are a result of excessive growth of normal tissue (benign tumors) or the overgrowth of abnormal cells (cancerous). Just finding a lump in the breast does not mean that its cancer. In fact, most breast lumps are not cancerous. The abnormal growths can alter the breast size although it is not usually the entire breast that may be affected. In the majority of cases though, the growth does not cause any visible lump or alteration breast size.
A breast abscess is a collection of pus within the breast tissue. It is usually a consequence of an infection and it may therefore be seen with mastitis. Fluid-filled cysts are small vesicles that occur in the breast tissue. Cysts are not filled with pus. A breast cyst is not uncommon and in most cases it is harmless. Some cysts may become filled with milk (milk cysts) which can become infected and develop into an abscess if left untreated.
Fluid within the breast, as part of inflammation, which may occur due to trauma in the breast or lymph when there is a lymphatic obstruction can also cause breast enlargement. Sometimes implants may be responsible if the implant ruptures. All of these factors may contribute to breast enlargement on one side more than other.