Can sleeping on your stomach or side cause breast cancer?

The sleeping position has often been discussed regarding postural slides, breathing, digestion, and musculoskeletal well-being. However, one of the primary issues raised by women is whether lying on one’s stomach or side increases the chances of developing breast cancer. There is a belief that the pressure put on the chest during sleep can harm breast tissues, restrict blood flow, and stop lymphatic drainage. Currently, no data prove that any of the sleeping positions cause breast cancer. Understanding what is just a temporary bodily discomfort and what is a real cancer risk factor can help put the anxieties into perspective.

Does pressure on the breasts during sleep cause cancer?

When lying in a prone position, pressure will be applied to the breasts. Likewise, sleeping on the side may create the condition whereby one breast lies against the mattress or the body, therefore making it prone to possible damage. Furthermore, for women with large breasts or breast tenderness, their sleeping position may affect their health. It should be noted, however, that it is not the position of sleeping that leads to transformation of the cells that cause breast cancer to develop. Breast cancer occurs as a result of various genetic factors and a variety of other conditions. Consequently, it has been proven that the sleeping positions applied do not cause any changes in the breast tissue that lead to cancer.

There is also no sufficient proof supporting the idea that sleeping in a specific position brings about the development of breast cancer through restriction of the blood flow or lymphatic drainage. The lymphatic system does not stop functioning during sleep, and the change of positions during sleep does not cause anything harmful to accumulate in the breasts.

Can sleeping on your side or stomach damage breast tissue?

For the majority of adults in good health, sleeping on the side or stomach does not harm the breast tissue. However, the breasts must endure pressure, resulting in temporary pain, which can be more pronounced during any stage of a woman’s menstrual cycle or any time of frequent hormonal changes. Sleeping on the stomach can also trigger discomfort at the level of the neck or the back since, in this position, the head must be turned in a certain way while sleeping. Likewise, sleeping on the side can sometimes provoke pressure in the shoulder or hip area depending on the sleeper’s position and the firmness of the mattress, causing troubles connected more to the issues of comfort rather than cancer prevention. Women who feel uncomfortable while sleeping may try to avoid this discomfort by adjusting the position in which they sleep, applying the appropriate pillow, or wearing a pulling bra, if they wish to do so.

Does sleeping position affect breast shape or sagging?

Certain women fret about possible breast sagging or changes in the way breasts look because of sleeping in certain positions, specifically on their side or on their stomach. The truth is that breast appearance is affected by a number of factors such as aging, elasticity of the skin, pregnancy, hormonal changes, or fluctuations in body weight. Despite the temporary discomfort that could be caused by sleeping in certain positions, there is not enough evidence to agree that a particular position can make a significant impact on the state of breasts or that it can increase the risk of breast cancer.

What are the actual risk factors for breast cancer?

Several elements affect the risk of breast cancer: age, genetic mutations passed down from one generation to another, the person's and family members’ health history, as well as the early breast changes suffered by the individual. Additionally, one’s lifestyle choices, such as consuming excessive alcohol drinks, leading an inactive lifestyle, and gaining weight after the onset of menopause will enhance the level of risk. The presence of these risk factors can signal that someone is more likely to develop breast cancer, but it does not mean that he or she will definitely get this disease. Many women diagnosed with breast cancer do not have any family history of this condition, and therefore understanding one’s own risk and undertaking necessary medical checks is clearly easier than worrying about one’s own sleep position.

When should women seek medical advice?

Women should not always assume that breast changes or sensations are due to their sleep posture. Any new lumps in breasts or armpits, unexplained swelling, skin changes, inverted nipples, or unusual discharge from the breast should prompt a visit to the doctor. Breast pain is rarely a cancer-related symptom, and some of the discomfort caused by the sleeping position may have nothing to do with breast cancer. However, if any new symptoms arise or existing problems continue, they should be evaluated.

Sleeping on one's stomach or side does not have a documented link to an increased chance of breast cancer. This means women should feel free to sleep however is most comfortable for them without worrying that it could lead to the illness. In terms of breast health, the most important aspects of prevention are understanding risk factors regarding one's individual health, being proactive about living a healthy lifestyle, adhering to screening recommendations, and consulting a healthcare professional about worrying symptoms.

The author is the director of surgical oncology at the CK Birla Hospital®, Delhi. 

 

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.