Armpit fat vs axillary breast tissue: What's the difference?

If you've noticed a bulge at the side of your breast or in your armpit you may be wondering why it occurs and if it's a cause for concern. While it may impact your confidence, the good news is that these lumps are totally normal and can occur in anyone, especially among women.

This armpit fat is a collection of extra folds of fat that are separate from the breast and sit slightly to the side. You might know it as the bra bulge.

Although extra fat is the most common reason for this bulge, it may also be caused by something called axillary breast tissue. In the article below, we break down the difference between armpit fat and axillary breast tissue and even cover some ways to target the bulge.

What contributes to fat in the armpits?

While genes play the biggest part in determining body fat distribution there are a few other factors that can contribute to armpit fat accumulation [1]. These can include:

• Wearing tight clothes for long periods of time
• Persistent poor posture (which is common for many of us at desk or office jobs)
• Overall excess body weight or anyone navigating obesity

Because excess weight can cause pockets of fat to form around parts of the arms and thighs, lowering your overall body weight should be the first place you look when looking for the causes of underarm fat.

Another reason for an extra bulge at the underarm can be caused by something called axillary breast tissue. Wondering which one applies to you? Let's have a look at the differences and how to spot whether it's breast tissue or underarm fat at play.

What is axillary breast tissue and is it different to armpit fat?

Axillary breast tissue is fibrous just like normal breast tissue and has nothing to do with fat accumulation. Whether the bulge is caused by extra breast tissue or fat, it's important to remind yourself that both are completely normal and not a cause for medical concern.

This axillary breast tissue can be found in the face, neck, or ear with 20% of cases appearing in the axilla or armpit [2].

When oestrogen and progestogen levels change, the axillary breast tissue may respond and swell in response to these shifting hormone levels. These fluctuations are most commonly caused by major life events in women, such as menstruation, pregnancy or menopause.

Axillary breast tissue tends to be responsive to hormonal fluctuations and can change shape and size throughout these fluctuations. In contrast, armpit fat won't quickly swell without a rapid weight increase or period of sudden weight gain. This may be one of the ways you determine whether you have extra fat or breast tissue in this area.

Can you exercise armpit fat away?

While spot training won't see weight loss in specific areas, it may still be possible to reduce armpit fat. Committing to an exercise routine focused on cardio and upper arms is the most surefire way to reduce overall body fat which may help get rid of armpit fat.

Although poor posture doesn't contribute to gaining excess weight, it can make armpit fat look more apparent. Standing with a forward rolling shoulder posture may make the bulge look bigger.

If you think this could be the cause, you might like to try grabbing a yoga mat and practising some posture-improving moves like the cow position, downward facing dog, and the cat position.

How can I lose armpit fat effectively?

Losing fat from target areas can be difficult, in fact, most studies show that spot reduction isn't possible [3]. However, losing weight in certain areas is possible by losing overall body fat.

This is best achieved through a combination of a healthy diet and exercise and may help in reducing the appearance of armpit fat. Upper arm weight training may also help the appearance of these areas.

While excess body fat can be a cause of excess armpit fat, it's important to note that it can occur regardless of overall body weight and in this case weight loss won't alter how it looks. If this is the case or if you're looking for a quick fix, you may have already started looking into surgical removal procedures. Let's dive into some of the pros and cons of these operations.

What's the deal with the armpit fat removal procedure?

While excess fat or breast tissue is not usually caused by a medical condition nor is it a cause for concern, if it's negatively impacting your life, you may be wondering about how armpit fat removal procedures work.

There are 2 operations most commonly used — liposuction and excision. So, what do you need to know about them?

Liposuction is the least invasive procedure for minimising armpit fat. While this procedure is relatively quick and it's likely you'll be able to go home on the same day, it may take a few months for bruising and swelling to disappear completely.

To surgically remove axillary breast tissue may involve liposuction, excision, or a combination of both. The type of procedure that's most suitable will depend on the cause of the excess breast tissue so it's best to consult a medical professional.

As with any surgery, it's important to know that there have been complications associated with both of these procedures [4]. Even though they are considered to be generally safe some possible complications may include:

• Nerve injury
• Shoulder stiffness
• Infection
• Scarring [5]

Another factor to consider is the cost. These procedures are priced anywhere from $2,500-$5,500 and because these procedures are completely cosmetic, it may be worth it to try alternative methods to lose armpit fat first.

Non-surgical approaches to armpit fat

While surgeries like liposuction and excision may be a good option for some, considering the high cost and long recovery time it may be best to look into other options first.

If you notice your armpit bulge fluctuates with hormonal changes this may be an indicator that it's breast tissue and not fat. If this is the case then a surgical procedure may be your only option to remove it, but remember cases of axillary breast tissue are quite rare and only present in 2-6% of women [6].

As the most likely cause of an armpit bulge is excess fat, the simplest way to reduce the appearance is to make some lifestyle and habit changes to target weight loss.

A holistic way to reduce armpit fat

If excess fat is causing your armpit lump then making some small changes to your lifestyle may just be all you need to shake the extra bulge. Starting an exercise regime might seem simple but knowing how to balance this with a low-calorie but nutrient-dense diet effectively can be challenging.

Feel like you've tried everything? Juniper’s Weight Reset Programme combines proven weight loss medication, health coaching and ongoing support to help you lose weight and keep it off. We prescribe a GLP-1 medication called Wegovy, which contains the active ingredient semaglutide.

Semaglutide is clinically proven to reduce your appetite and make you feel fuller for longer, while also reducing cravings by targeting the rewards centre in the brain. 

For long-term success, changing your eating and movement habits is also crucial, which is why we offer a comprehensive programme that includes 3 core pillars of lifestyle change with the assistance of our UK clinicians.

We can help you break habits that might be impacting your weight and help you hit your weight loss goals sooner.