If you're concerned with axillary breast tissue in your armpit, you're not alone. According to a May 2014 article in the American Journal of Roentgenology, up to 6 percent of the population has accessory breast tissue.
If you have axillary breast tissue, exercise is not likely to make a big difference. Excision and liposuction are the recommended treatments. If the tissue is not breast tissue and just excess fat, exercise and a healthy diet can help.
Because this breast tissue is made up of some fatty elements, it's possible that exercise and fat loss could affect the appearance of excess tissue, but it is not a proven treatment. Surgical excision and liposuction are the most commonly used treatments for axillary breast tissue.
Read more: The Ultimate Guide to Fat Loss
What Is Axillary Breast Tissue?
According to an article published in the April 2017 issue of the Journal of Ultrasound in Medicine, axillary breast tissue, also known as accessory breast tissue or ectopic breast tissue, is excess breast tissue that fails to regress after normal embryological development.
This type of breast tissue is most frequently located in the axilla — the armpit — along the mammary ridge or milk line, a thickened band of tissue extending from the armpit to the groin, according to an article in the International Journal of Surgery Case Reports in May 2019.
However, the authors of the American Journal of Roentgenology article say this type of tissue can also be located on the face, back of the neck, mid-back, buttocks, vulva, hip, shoulder and thigh.
Axillary breast tissue may be asymptomatic, have no visual appearance or may appear as bulges on either or both sides of the breasts under the armpit. One side may be more enlarged than the other. It may also become visible or increase in appearance due to hormonal changes during puberty, menstruation and pregnancy.
Axillary Breast Tissue and Exercise
Axillary breast tissue in the armpit isn't any different to other breast tissue. It's comprised of fibrous and fatty tissues. When you lose a lot of weight, your breast size may decrease because you lose some volume in your breasts. Therefore it's likely that axillary breast tissue would also decrease in size — but it will not disappear, just as your breasts will not disappear with weight loss.
If you have excess body fat, it's a good idea to exercise regularly and eat a calorie-controlled diet – for your overall health, if nothing else. Reducing the appearance of axillary breast fat is a bonus, but don't expect miracles.
If you do see positive changes from fat loss, it may take a long time to see changes where you want them. When you lose total body fat, it comes from all over your body, and it might come from your face, thighs and stomach before it affects your breasts and underarm breast tissue. And, although targeted chest exercises can help to firm the pectoral muscles of your chest, they will not affect the appearance of underarm breast tissue.
The only proven ways to get rid of axillary breast fat, according to the American Journal of Roentgenology article, are surgical excision and liposuction. Excision is the treatment of choice when the excess tissue causes discomfort as a larger volume of tissue can be removed. When removal is for aesthetic purposes, liposuction may be all that's necessary. In some cases excision and liposuction will be used together.
The Journal of Ultrasound in Medicine article explains that axillary breast tissue is a normal occurrence, not an abnormality. It is not dangerous and need not be removed except in the case where it causes discomfort or for aesthetic reasons.
Get Rid of Underarm Fat
Axillary breast tissue is not the same thing as excess underarm fat, according to the Journal of Ultrasound in Medicine. If you have not received a medical diagnosis, what you think is axillary breast tissue may just be excess body fat that has collected in your underarm area. It's best to consult your doctor so you know exactly what you are dealing with.
If it is just excess body fat, eating less and exercising more can make a significant difference. But what kind of exercise is best and how much should you do? The Physical Activity Guidelines for Americans from the U.S. Department of Health & Human Services are a good place to start.
According to these guidelines, adults should get at least 150 to 300 minutes of moderate-intensity, or 75 to 150 minutes of vigorous-intensity, aerobic exercise each week. Examples of moderate-intensity exercise include brisk walking, dancing, gardening, biking at a place slower than 10mph, playing doubles tennis and doing water aerobics, according to the American Heart Association.
Vigorous activities include running, hiking uphill, swimming laps, aerobics classes, heavy yard work, singles tennis, jumping rope and cycling at a speed of more that 10mph. For even more fat loss benefits, try to exceed these recommendations. However, if you haven't previously done any exercise, take it slow and gradually increase the time you spend being active.
The U.S. Department of Health & Human Services also recommends that adults do some type of resistance training for the entire body at least two days a week. This could mean going to the gym and lifting weights, doing body-weight exercises at home or taking a class such as Pilates or yoga.
Focus on the whole body when weightlifting — not just the area around the breast tissue. Building muscle mass helps burn fat because muscle is more metabolically active than fat. The more muscle you have, the more calories your body will burn even while you are at rest, explains the Mayo Clinic.
Another reason that it's important to see your doctor to determine whether your underarm tissue is breast tissue or simply fat is because axillary breast tissue is subject to the same conditions and diseases as normal breast tissue. These could be benign cysts or tumors, or they could be malignancies such as ductal cancer, according to the Journal of Ultrasound in Medicine.
- American Journal of Roentgenology: "The ABCs of Accessory Breast Tissue: Basic Information Every Radiologist Should Know"
- Journal of Ultrasound in Medicine: "Sonographic Findings of Accessory Breast Tissue in Axilla and Related Diseases"
- International Journal of Surgery Case Reports: "Invasive Carcinoma in Accessory Axillary Breast Tissue: A Case Report"
- U.S. Department of Health & Human Services: "Physical Activity Guidelines for Americans"
- American Heart Association: "American Heart Association Recommendations for Physical Activity in Adults and Kids"
- Mayo Clinic: "Metabolism and Weight Loss: How You Burn Calories"