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When you're young, your body undergoes a whole lot of changes (hello, puberty). But once you reach adulthood, you might expect certain aspects of your physique to look — more or less — the same for most of your life.
That's why you may be confused when your breasts seem to change over the years. But it's true: Your boobs can grow, shrink or change shape throughout your life.
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While most breast changes are normal, some may hint at an underlying health issue. So, how can you tell the difference?
Here, Sheryl A. Ross, MD, ob-gyn and author of She-ology: The Definitive Guide to Women's Intimate Health. Period, explains why your breasts may change shape and when to see a doctor about shifts in the size, shape or texture of breast tissue.
A Note on Language
Here at LIVESTRONG.com, we try to avoid language that implies a sex or gender binary in favor of more inclusive language, but we sometimes include words like "men" or "women" when quoting an expert or other original source material for the sake of accuracy.
1. You’re Pregnant (or Postpartum)
Turns out, breast changes are one of the first signs you're expecting.
"During pregnancy, the hormonal effects of estrogen can make your breast tissue feel swollen, full, tender and enlarged," Dr. Ross says. In fact, your breasts can grow two to three sizes larger during pregnancy, she says.
And breast size isn't the only thing that could change. Other changes could include the following, per Dr. Ross:
- Stretch marks may appear (due to the fast growth of the breasts)
- Nipples (and your areola) can become darker, more prominent, tender and sensitive
- Nipples may emit discharge or become crusty
- The veins of the breasts may become more prominent
You can also expect changes in your breasts after giving birth if you decide to breastfeed. Your breast size and shape may change as they fill with milk. And in some people, "breast tissue tone can be noticeably saggy following breastfeeding," Dr. Ross says.
2. You Have Your Period
If you've ever felt like you needed a bigger bra size during your monthly menses, you're not imagining things.
"Painful, tender and swollen breasts due to period hormones are common, especially a week or two before your period," Dr. Ross says.
The main culprit for these cyclical breast changes is the hormone progesterone, which triggers the development of milk glands in preparation for a possible pregnancy, according to Johns Hopkins Medicine. These enlarged milk glands are also the reason your breasts may feel especially lumpy before your period arrives, too.
The good news? "Once your period starts [and your body recognizes that you're not pregnant], these symptoms quickly go away," Dr. Ross says.
Warning
If you notice a lump in your breast — or another new breast change — that doesn’t subside when your period does, see your doctor, as these might be signs of a more serious condition such as breast cancer.
3. It’s Your Birth Control
While you may take the pill to prevent pregnancy or regulate hormonal imbalances, hormonal birth control can also have other inadvertent effects, like causing your breasts to change shape.
"The hormonal effects of oral contraception, i.e., the 'pill,' can make the breasts feel swollen, tender, enlarged and more sensitive," Dr. Ross says.
This breast enlargement is due in part to an in increase in fluid retention caused by hormones such as estrogen and progesterone, according to the Mayo Clinic. When your body retains extra water, it can often create uncomfortable swelling in your breasts, which temporarily increases their size.
4. You’ve Gained or Lost Weight
Ever notice that your breast size fluctuates with the number on the scale?
"Breast tissue is made up of fat, so significant weight gain and loss can have an impact on breast size," Dr. Ross says.
It's true: If you put on a few pounds, you may also go up a bra cup size as the fatty tissue in your breasts increases. And the opposite is true, too: When you lose fat, your breasts might also shrink.
You may also experience a change in breast shape after weight loss. For example, some people who've shed a large amount of weight may see a drooping or "pancaking" effect in their breasts, according to a small July 2019 study in the Journal of Cutaneous and Aesthetic Surgery.
While there may not be a way to prevent this, there are ways to firm up saggy breasts after weight loss.
5. You’ve Gained Muscle
Strength training can also change the appearance of your breasts. In fact, lifting weights may, well, lift your boobs a bit. This is especially true if you focus on sculpting your pectoral muscles, i.e., your chest muscles that lie under your breast tissue.
"Weight-training your chest muscles — along with [bodyweight exercises like] push-ups — helps strengthen these important muscles, which keeps the breasts perky and minimizes sagging," Dr. Ross says.
So if these muscles grow larger, your breasts may also appear larger or more firm.
6. You’re Getting Older
When you think about the symptoms of menopause, hot flashes are likely the first thing that comes to mind. But breast changes are also a common effect of menopause.
This is because of "the loss of estrogen during menopause, which makes breast glandular tissue smaller, fattier and less dense," Dr. Ross says.
Estrogen is in charge of keeping breasts full and prepared to produce milk during childbearing years. But as estrogen decreases in menopause, breast tissue can become less elastic, per Johns Hopkins Medicine. This is why your breasts may shrink and appear saggy, Dr. Ross says.
On the other hand, an increase in cleavage as you age isn't unheard of, either.
While "it's not typical for breast tissue to grow larger during menopause, one in five women do go up one bra size after menopause," Dr. Ross says.
7. You Have Fibrocystic Breasts
Fibrocystic — or dense — breasts can also affect breast shape and size. The condition causes a lumpy or ropelike texture in your breast tissue, is completely benign and affects about half of people with breasts between ages 20 and 50, per the Cleveland Clinic.
"Fibrocystic breasts are classically lumpy and tender," Dr. Ross says, adding that one or both breasts may be affected, so you may notice a change in shape of just one breast.
These lumps in your breasts can form and disappear suddenly, and they're thought to be related to hormonal fluctuations, according to the Cleveland Clinic. Estrogen, in particular, may play a role, which is why these lumps tend to show up before your period.
Warning
While fibrocystic breast changes are normal, always talk to your doctor if you discover any new growths or masses in your breast tissue, as this could be a sign of breast cancer.
8. You’re Consuming Caffeine or Nicotine
Believe it or not, you might be prone to breast shape changes if you're a big coffee drinker or a heavy smoker.
This is because both caffeine and nicotine can cause breast tenderness and pain by clamping down the blood vessels in your breast tissue. Consuming large amounts of both can also increase breast sensitivity, especially before your period, Dr. Ross says.
"Some women also experience breast enlargement as well," Dr. Ross adds.
What's more, caffeine may also potentially exacerbate fibrocystic breast changes, according to the Cleveland Clinic.
This is why it might be a good idea to limit coffee and other caffeinated foods, including tea, soda and chocolate. And of course, quitting nicotine and other tobacco products is good for your overall health, too.
9. You Have Breast Cancer
"Sometimes a shift in breast shape or size can indicate something more serious like breast cancer," Dr. Ross says.
Depending on the extent of the cancer, a malignant mass can alter the size and shape of your breast tissue.
Along with shape changes, other signs of breast cancer to watch out for include the following, per the National Library of Medicine:
- A lump or thickening in or near the breast
- Nipple discharge, tenderness or retraction (turning inward)
- Skin irritation, dimpling, redness or scaliness
In addition to the disease itself, some breast cancer therapies can also affect the appearance of your breasts.
For example, a "lumpectomy, mastectomy and radiation treatment can change the size, shape, sensitivity and color of the skin and [cause] other unpredictable breast nuances," Dr. Ross says.
Warning
Always discuss any changes in your breast tissue with your health care provider to rule out serious issues like breast cancer.
When Should You See a Doctor About Breast Changes?
While many breast changes are benign, some shifts in the size and shape of your breasts may indicate an underlying health problem.
For this reason, "it's important to become familiar with the feeling of your breast tissue, as you could be the first person to detect something that is not normal," Dr. Ross says.
"Breast tissue can be intimidating in the beginning, but once you're familiar with your own normal lumps and bumps, you will be able to find abnormal changes if they occur," she adds.
A good way to keep track of "your normal" is by performing monthly self-breast exams. A self-breast exam involves using your eyes and hands to inspect your breasts to identify any changes.
What types of things should you be looking or feeling for? Pay attention to the following symptoms, which may signal a possible breast abnormality, per Dr. Ross:
- Skin changes or irritation
- Nipple discharge
- New lumps or bumps that feel like a piece of hard candy or gravel in the breast tissue
If you notice any of the above symptoms — or any other new breast changes — discuss them with your doctor immediately. Your doctor may perform a mammography or breast ultrasound to determine if there is a cause for concern, Dr. Ross says.
Tip
Whether you detect the above warning signs or not, you should get regular mammogram screenings every two years starting at age 40, per the U.S. Preventive Services Task Force.
That all said, hormonal changes can affect breast tissue, so always take into account where you are in your menstrual cycle if you find a new breast lump. As we know, hormones like progesterone cause your milk glands to grow just before your period, making your breast tissue temporarily lumpy.
That's why "it's always best to check your breasts immediately following your period (days four through eight are ideal)," Dr. Ross says. "This time of the month is when your breasts will have the least amount of hormonal influences."
How to Perform a Self-Breast Exam
Follow these steps, according to the Mayo Clinic.
First, inspect your breasts visually:
- Sit or stand shirtless and braless in front of a mirror with your arms at your sides.
- Face forward and look for puckering, dimpling or changes in size, shape or symmetry.
- Check to see if your nipples are inverted (turned in).
- Inspect your breasts with your hands pressed down on your hips.
- Inspect your breasts with your arms raised overhead and the palms of your hands pressed together.
- Lift your breasts to see if ridges along the bottom are symmetrical.
Next, perform the manual part of the breast exam:
- Use the pads, not the very tips, of three fingers for the exam.
- Use light pressure to feel the tissue closest to the skin, medium pressure to feel a little deeper and firm pressure to feel the tissue closest to the chest and ribs. Be sure to use each pressure level before moving on to the next spot.
- Use a methodical technique to ensure you examine your entire breast. For instance, imagine the face of a clock over your breast or the slices of a pie. Begin near your collarbone and examine that section, moving your fingers toward your nipple. Then move your fingers to the next section.
The Bottom Line
Though many changes in breast size or shape are benign — and common — you might still have feelings about how they look. And that's totally natural.
With so many factors affecting your breasts, you may be unable to control their shifting appearance. But you do have power over how you perceive them. And it may be helpful to remember that "different is normal," Dr. Ross says.
"You know that saying about how no two snowflakes are alike? Well, the expression could refer to breasts as well," she says.
"Any body parts that come in a set of two are never exactly a mirror image of each other — your ears, eyes, lips, breasts and labia are all slightly different in shape and size, and this is completely normal."
As long as your breasts are healthy, try not to sweat any visual change.
- Johns Hopkins Medicine: “Normal Breast Development and Changes”
- Mayo Clinic: “Water retention: Relieve this premenstrual symptom”
- Journal of Cutaneous and Aesthetic Surgery: “Mastoplasty after Massive Weight Loss: Redefinition and Stabilization of the Breast Mound with Submuscular Autoprosthesis”
- National Library of Medicine: “Breast cancer”
- Mayo Clinic: “Breast self-exam for breast awareness”
- U.S. Preventive Services Task Force: "Breast Cancer: Screening"
Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.