Breast Changes Throughout Your Menstrual Cycle

Breast screening is an essential part of women’s health. If it’s time for you to get regular mammograms, keep your appointments so that any changes can be detected as soon as possible. In between your mammograms and well-woman breast exams, do a self-exam every month.

If you pay attention to your breasts, though, you realize that they go through cycles each month, just like your period. Once you understand how your breasts change with your menstrual cycle, it’s easier to time your monthly self-exams.

Expert physicians Joseph Calandra, MD, and Karen Mass, MD, encourage you to familiarize yourself with your own breasts so you know when something changes. At Mass Medical Imaging, we perform mammograms and other breast screenings at our Lake Forest, Illinois, office to ensure your breasts are healthy or to catch breast cancer as early as possible.

What kinds of breast changes can you expect during your menstrual cycle? Below is a summary.

The menses phase

Your menstrual cycle consists of several overlapping phases. The menses phase starts on Day One, when you first begin to see blood from your period.

You shed the blood-rich lining of your uterus because your egg didn’t get fertilized, a pregnancy didn’t occur, and you don’t need the lining anymore. It's normal to bleed for anywhere from 3-7 days.

During menstruation, your breasts may no longer feel tender, as they might during other parts of your cycle. Usually, any breast pain subsides during or directly after your period, too.

The follicular phase

The follicular phase also starts on Day One. Even though you’re in the middle of shedding your uterine lining, your body’s already preparing for a new ovulation. The follicular phase ends when your body releases an egg, usually around Day 15, depending on the length of your cycle.

During the follicular phase, your body produces more estrogen. The estrogen causes you to start rebuilding that shed uterine lining, in preparation for the next egg. 

Rising estrogen levels also cause your milk glands (i.e., breast lobules) to swell. Your breasts may start to feel lumpy and tender again, just about a week or so after your period ends.

Your body also produces follicle-stimulating hormone (FSH), which causes your ovaries to release a new egg mid-cycle. The follicular phase ends after the egg is released.

The luteal phase

As your mature egg leaves your ovary and travels through a fallopian tube to reach your uterus, your body produces another hormone, called progesterone. Progesterone helps your uterine lining grow thick with blood and nutrients in case that egg gets fertilized and implants in the lining.

Your breasts are usually the largest and most tender during the luteal phase, which lasts from about Day 14 or 15 to the end of your cycle, on Day 28 or so, when you menstruate again.

During the luteal phase, your breasts prepare to feed a baby in case your egg is fertilized. Your breasts may swell so much that your bra feels tight. 

You might also notice that your breasts don’t feel smooth. They may have a lumpy or chunky feeling. That’s normal during this phase of your menstrual cycle. If they still feel ropy or lumpy after your period, you may have benign cysts or another condition.

The best time for a breast exam

Since fluctuating hormones influence your breast size, consistency, and sensation while you’re ovulating, it’s best to time your breast exam after your period starts and before you ovulate. Usually, 3-5 days after the start of your period is the best time for your exam. Your premenstrual swelling, lumpiness, and tenderness should have subsided.

Be sure to alert us if you notice anything unusual during your exam, such as a lump. Also, let us know if your nipples bleed, discharge other fluid, or turn inward.

Are you ready for a mammogram? Or do you have questions about something you’ve found in your self-exam? Call our caring and expert team or use our online appointment form to book a breast screening today.