Why do my armpits smell so bad... even after a shower?

You take a daily shower, apply deodorant and still your armpits smell bad. What are you doing wrong? This is such a common problem, so don’t “sweat it”.  Even this dermatologist had the problem herself,  but figured out the solution that works. You can be free of body odor by understanding causes and easy fixes. As a doctor, I will say,  while body odor can be managed,  if your smelliness persists, it could be a sign you need medical attention. Learn more, keep reading.

What to know about armpit odor.

First, smelly underarms are not your fault. There is a biologic set up for body odor.

Medical terms:

bromhidrosis= body odor

hyperhidrosis=excessive sweating

Interestingly, these two do not always go together. Some of us who sweat excessively may not have odor and those who have odor may sweat very little. How could that be? Because while moisture is at the root of armpit odor, the amount of sweat is not the only key to stink. We may produce so much moisture that it dilutes the odor causing mechanism. Conversely, very little sweat doesn’t always mean no armpit smell. It is not just moisture that causes odor. So, even when you use an antiperspirant that blocks sweat, you can still notice some stinkiness. There is more to the body odor story.

These are the two types of sweat glands:

apocrine glands = Specialized sweat glands only found in armpits, nipples, and the genital region that start functioning at puberty and are in large part triggered by hormones. They deposit onto the skin via the hair follicle.

eccrine glands = The majority of the body’s sweat glands.  Located all over the body, particularly on underarms, scalp, palms and soles and are triggered by strenuous activities and stressful conditions. These maintain ideal body temperature. They are not dependent on hair follicles, as they deposit through a sweat duct directly onto the skin surface.



Sweat glands get much of the blame for body odor but in reality are only part of the equation. These glands keep your  body temperature in a healthy range by emitting moisture (sweat) that as it evaporates, cools the skin’s surface and internally protects your organs from overheating. Sweat at its source is odorless. Once it reaches the skin’s surface, it meets up with odor producing bacteria. What occurs is the perfect storm of skin surface bacteria, dead skin cells and trapped dampness that makes my armpits smell so bad. Of note, bacteria is important for the skin microbiome. Not all bacteria are setting off the body odor process. However, specific bacteria known as corynebacterium and certain species of staphylococci which are found in underarm skin, produce thioalcohol when they interact with elements of sweat and skin debris. Thioalcohol is the pungent, enzymatically derived end product of human skin biochemistry that we know as body odor.


Add these up and you get armpit smell

Moist skin: If you enter a damp basement or a humid yoga studio...what do you notice? Very possibly you will encounter a musty scent. Prolonged damp conditions are a breeding ground for bacteria and fungus. The proliferation of these microbes creates a detectable unpleasant smell. Ditto on the skin. The body odor is partly due to trapped moisture leading to sweat smell.

Location: Skin folds trap moisture and are the home of specific bacteria such as corynebacteria, propionibacteria and staphylococci that produce a by-product known as a thioalcohol (as mentioned above), which causes armpit odor. Location, location location. Armpits are damp, do not get air flow, are prone to skin cell (keratinocyte) build up as well as product build up (layers of residue from soaps, perfumes and deodorant) and top it off, they have odor producing bacteria hence they serve as the right home for stink.

Hormonal changes: Hormones at both ends of the age spectrum from adolescence to later in life, play a part in body odor. This is why it is around puberty when most of us first start to notice smelly armpits. Then there are  night sweats that accompany menopause that may add to  the chance of body odor.  Stressful circumstances can increase the levels of adrenaline in the body and affect the production of apocrine gland and eccrine gland secretions.


Other characteristics that may worsen underarm odor

Hair follicles and underarm hair— can trap moisture and dead skin cells which odor causing bacteria love

Skin pH— the skin has a protective acidic set point known as the acid mantle. If the skin’s pH is much higher (alkaline) or way too low (acidic), the skin barrier and the microbiome (good bacteria) get perturbed and this can lead to smelly underarms.

Some foods— cayenne, cumin, curry, garlic, onions, other spices, red meat, cruciferous vegetables like broccoli

Some medications — ask your doctor

Clothing—some fibers hold on to moisture and odor if they are not constructed from moisture- wicking fabric or are densely woven.

Medical conditions: various diseases and medical conditions can put you at greater risk of body odor. A short list includes, infections, kidney disease, liver disease, obesity, thyroid disease and many more. Advise your medical professional if you have a worsening or hard to control body odor (anywhere on the body).


What can you do to minimize smelly armpits and body odor anywhere:

Shower with antibacterial soap — but be careful. Benzoyl peroxide soap is a good choice but be aware that it can cause skin irritation and may bleach fabric. A pH balancing cleanser that is not too harsh is the best choice. Surface Deep Skin Wash is a great example.

Gently exfoliate using a washcloth or anti-odorant wipe like Surface Deep Anti-Odorant Pads. Keeping the skin free of dead skin cells, oils and dirt  helps minimize the chance of odor developing. Be sure not to over do it. Harsh scrubs are not advised.

Make sure no residue is left on the skin. Why? Because even the best smelling soap can create build up that will invite odor in spite of great attempts made at personal hygiene.

Wear clothing that is made of moisture wicking fabric, like yoga pants or bike shorts that aim to keep sweat from being trapped. Notably, fibers such as lycra, polyester, nylon, merino wool keep the dampness away from skin and can help reduce risk of body odor.

Remove damp or wet clothing and dry off as soon as possible.

Keep skin dry by using a hair dryer to air-dry your pits after a shower. Do not rub delicate underarm skin too aggressively. Air drying is a gentle and effective alternative.

Overly dry skin is to be avoided too. If your antiperspirant is making your skin overly dry and chapped, opt for an aluminum free deodorant.

Persistent bromhidrosis or hyperhidrosis can be a sign of a serious medical condition See your doctor for advice.


*The above information is not intended as medical advice.