Underarm Sweating

What Causes Underarm Sweating? Information on the Causes and Diagnosis of Axillary Hyperhidrosis, Antiperspirants, Botulinum Toxin, and Other Treatment Options.

Underarm Sweating (Axillary Hyperhidrosis)

Underarm sweating is part of the body's natural temperature-regulating mechanism. Increased sweating during hot weather, physical activity, fever, stress, excitement, or hormonal changes can be a normal physiological response. However, if sweating occurs regardless of the body's need to cool down, continues in cool environments, or becomes intense enough to cause constant and noticeable wetness on clothing, it may be excessive underarm sweating, known as axillary hyperhidrosis. Axillary hyperhidrosis is not just sweating that appears in hot weather or during exercise. In some people it can also occur at rest, during everyday conversations, or without any obvious trigger. Primary axillary hyperhidrosis usually affects both underarms in a similar way and decreases during sleep. Excessive underarm sweating is not a directly life-threatening condition. Nevertheless, it can affect clothing choices, work life, social situations, skin health, and day-to-day comfort.

What Is Axillary Hyperhidrosis?

Axillary hyperhidrosis is excessive sweating that mainly affects the underarm area. The underarm contains both eccrine and apocrine sweat glands. The heavy sweating associated with hyperhidrosis is mainly related to increased activity of the eccrine sweat glands. Sweat gland function is influenced by the autonomic nervous system and the sympathetic nerve pathways. People with primary axillary hyperhidrosis do not necessarily have more sweat glands than normal. The condition is usually related to normally structured sweat glands being stimulated more than usual.

Underarm sweating can occur at different levels of severity:
  • Intermittent mild dampness
  • Small sweat marks on clothing
  • Noticeable wetness in the underarms on a regular basis
  • Needing to change clothes during the day
  • Sweat marks spreading over a large part of the clothing
  • In severe cases, sweat running down from the underarms
Axillary hyperhidrosis can occur on its own or together with excessive sweating of the hands, feet, face, or scalp.

How Does Underarm Sweating Affect Daily Life?

At first glance, axillary hyperhidrosis may seem like a condition that only leaves sweat marks on clothing. However, persistent or severe sweating can affect a person's daily decisions and behavior.

Excessive underarm sweating can lead to:
  • Avoiding certain clothing colors
  • Prioritizing hiding sweat marks when choosing clothes
  • Needing to change clothes during the day
  • Carrying a spare change of clothes
  • Avoiding raising the arms
  • Feeling uncomfortable in meetings or social settings
  • Anxiety about sweat marks being noticed
  • Avoiding certain social or professional situations
  • Moisture-related discoloration or fabric changes in clothing
Prolonged moisture can also affect the skin of the underarms.

As a result, the following may occur:
  • Irritation
  • Itching
  • Redness
  • Friction-related tenderness
  • Softening of the skin
  • Susceptibility to certain fungal or bacterial skin problems
  • Changes in skin color
  • Odor


Worry about sweating being noticed can increase sympathetic nervous system activity. This can create a cycle in which sweating increases anxiety and anxiety increases sweating. For this reason, axillary hyperhidrosis is not regarded as merely a cosmetic problem.

What Is Primary Axillary Hyperhidrosis?

Primary axillary hyperhidrosis is excessive underarm sweating for which no other disease or medication effect that could explain the sweating has been identified. It usually begins in childhood, adolescence, or young adulthood.

Primary axillary hyperhidrosis usually:
  • Affects both underarms in a similar way
  • Is recurrent
  • Is more noticeable during waking hours
  • Decreases or disappears during sleep
  • May increase with heat, stress, or excitement
  • May begin without an obvious trigger
  • May also be seen in other members of the same family
In some people, excessive sweating of the hands, feet, face, or scalp may also accompany the condition. The sweat glands are usually structurally normal. Greater-than-normal nerve stimulation reaching the sweat glands is considered one of the main mechanisms.

What Is Secondary Underarm Sweating?

Excessive underarm sweating can sometimes occur in connection with another disease, a physiological change, or medications being taken. This is called secondary hyperhidrosis.

Features that may suggest a secondary cause include:
  • Sweating that starts for the first time in adulthood
  • Symptoms that increase markedly over a short period
  • Noticeably more sweating in one underarm than the other
  • Sweating that continues during sleep
  • Sweating that affects large areas of the body
  • Accompanying fever, palpitations, or shivering
  • Unexplained weight changes
  • Marked fatigue or weakness
  • Sweating that appears after starting a new medication
Conditions that may be associated with secondary sweating include:
  • An overactive thyroid gland
  • Low blood sugar
  • Diabetes
  • Menopause and hormonal changes
  • Febrile illnesses and certain infections
  • Certain neurological diseases
  • Conditions affecting the autonomic nervous system
  • Certain systemic diseases
  • Use of alcohol or certain substances
  • Side effects of certain medications


Even if a medication is thought to be increasing sweating, it should not be stopped without a physician's evaluation.

Is Underarm Sweating Genetic?

Primary axillary hyperhidrosis can occur in more than one person within the same family. Excessive sweating in a mother, father, sibling, or other close relative may suggest that a genetic predisposition plays a role. However, not everyone with axillary hyperhidrosis has a family history. Even within the same family, the age at which sweating begins, its severity, and the body areas affected can differ.

Why Does Stress Increase Underarm Sweating?

Stress, excitement, embarrassment, and anxiety can increase sympathetic nervous system activity. This can lead to greater stimulation of the sweat glands in the underarms. In people with primary axillary hyperhidrosis, this response may be more pronounced. Even the thought that sweat marks will be visible in a meeting, during a presentation, or in a social setting can trigger a new stress response and increase sweating. This does not mean that axillary hyperhidrosis is purely psychological. Axillary hyperhidrosis is a physical sweating disorder; however, emotional triggers can affect the severity of symptoms.

Does Underarm Sweating Continue During Sleep?

Primary focal axillary hyperhidrosis usually decreases markedly or stops completely during sleep. If regular and heavy sweating occurs throughout the night, other causes are also considered.

These may include:
  • A very warm sleeping environment
  • Febrile illnesses
  • Certain infections
  • Hormonal or metabolic conditions
  • Certain medications
  • Night sweats affecting the body as a whole


Night sweats alone do not establish the diagnosis of a specific disease. The time of onset, the distribution of sweating, and other accompanying symptoms are evaluated together.

Are Underarm Sweating and Body Odor the Same Thing?

No. Although excessive sweating and body odor can be related, they are not the same condition. Sweat secreted by the eccrine sweat glands usually has no noticeable odor. Odor can develop when microorganisms on the skin, particularly bacteria, interact with skin secretions. The underarm also contains apocrine sweat glands. When the secretions of these glands are broken down by bacteria on the skin, they can contribute to body odor. Heavy sweating can make odor more noticeable by keeping the area moist for long periods. However, not everyone with axillary hyperhidrosis has noticeable body odor. Similarly, people who do not sweat excessively can also have underarm odor. Marked and persistent body odor may be referred to as bromhidrosis.

How Is the Severity of Underarm Sweating Assessed?

The severity of axillary hyperhidrosis is not determined solely by the amount of sweat produced.

The assessment may take into account:
  • How often sweating occurs
  • Whether both underarms are affected
  • The size of sweat marks on clothing
  • The need to change clothes during the day
  • Restrictions on clothing choices
  • Avoidance of social situations
  • Effects on professional activities
  • Development of skin irritation or infection
  • Response to previous treatments


In mild axillary hyperhidrosis, there may be intermittent dampness, and daily life may be largely unaffected. In moderate hyperhidrosis, visible sweat marks may appear regularly, clothing choices may be restricted, or there may be a need to change clothes. In severe cases, large areas of clothing can become wet, and sweating can markedly affect social, professional, or daily activities. This grouping is not a definitive laboratory classification.

How Is Axillary Hyperhidrosis Diagnosed?

The evaluation is mostly based on the medical history and physical examination.

When taking the history, the following may be assessed:
  • The age at which sweating began
  • How long it has been going on
  • Whether both underarms are affected
  • Whether it continues during sleep
  • Situations that increase sweating
  • Excessive sweating in other areas of the body
  • Its impact on daily life
  • Medications being taken
  • Coexisting conditions
  • Family history
  • Fever, palpitations, shivering, or unexplained weight changes
  • Previous treatments


If there is a typical history consistent with primary axillary hyperhidrosis, comprehensive laboratory testing is not necessary for everyone. When secondary hyperhidrosis is suspected, depending on the person's symptoms, tests such as the following may be considered:
  • Blood sugar
  • Thyroid function tests
  • Blood count
  • Kidney and liver function
  • Tests related to infection or hormones
  • A review of medications being taken

Are Tests Done for Underarm Sweating?

Certain tests can be used to assess the distribution or amount of sweating. The starch-iodine test can help highlight areas of active sweating. It can be used to show the distribution of the sweating area, particularly when a localized treatment is planned. Gravimetric measurement can also be used to assess the amount of sweat produced over a given period of time. These tests are not necessary for everyone. In treatment planning, the medical history and the impact of sweating on daily life often provide more information than a single measurement of sweat volume.

Are There Other Conditions That Resemble Underarm Sweating?

A feeling of moisture or discomfort in the underarms does not always mean primary axillary hyperhidrosis.

Similar symptoms may be related to:
  • Hot weather
  • Intense physical activity
  • Fever or infection
  • Low blood sugar
  • Thyroid diseases
  • Anxiety or panic attacks
  • Side effects of certain medications
  • Diseases affecting the autonomic nervous system
  • Certain skin diseases
  • Tight or poorly ventilated clothing
  • Hot working environments


Sweating that is consistently prominent in only one underarm is not typical of primary focal hyperhidrosis. If one-sided sweating is accompanied by pain, numbness, weakness, or noticeable skin changes, other causes are also considered.

How Is Treatment for Underarm Sweating Planned?

The treatment approach is not the same for everyone.

Planning takes into account:
  • Whether the sweating is primary or secondary
  • Its severity
  • Its impact on daily life
  • Skin type
  • Medications being taken
  • Coexisting conditions
  • Previously used methods and the response to them


In primary axillary hyperhidrosis, treatment usually starts with less invasive methods.

Options that may be considered include:
  • Changes in daily habits
  • Antiperspirants
  • Certain topical medications
  • Certain oral medications
  • Botulinum toxin treatments
  • Iontophoresis in selected cases
  • Localized procedures targeting the sweat glands
  • Psychological or behavioral approaches when needed
  • Thoracic sympathetic surgery in carefully selected cases


If one method is not sufficient, this does not automatically mean that surgical treatment is required. The goal of treatment is not necessarily to eliminate sweating completely in every case, but to reduce it to a level that does not significantly affect daily life, the skin, or social functioning.

What Can Be Done in Daily Life?

Daily adjustments do not eliminate the underlying mechanism of primary axillary hyperhidrosis, but they can reduce some of its effects.

These may include:
  • Choosing breathable clothing
  • Changing clothes that become wet
  • Keeping the underarms clean and dry
  • Avoiding products that persistently irritate the skin
  • Identifying personal sweating triggers
  • Increasing air circulation in hot environments
  • Using underarm pads to protect clothing when appropriate
  • Adjusting skin care if skin irritation develops


In some people, alcohol, spicy foods, caffeine, nicotine, or intense stress can increase sweating. Triggers can vary from person to person.

What Is the Difference Between a Deodorant and an Antiperspirant?

Deodorants and antiperspirants do not serve the same function.

Deodorants

They are mainly intended to reduce or mask body odor. They usually do not reduce the amount of sweat.

Antiperspirants

They aim to reduce the amount of sweat reaching the skin surface by temporarily affecting the sweat ducts. Some products may have both deodorant and antiperspirant properties, but the two terms do not mean the same thing.

Are Antiperspirants Used for Underarm Sweating?

Antiperspirants containing aluminum salts are among the first nonsurgical methods that may be considered for axillary hyperhidrosis. These products aim to reduce the amount of sweat reaching the skin surface by temporarily affecting the sweat ducts. Possible side effects include:
  • burning,
  • itching,
  • redness,
  • dryness,
  • skin irritation
Applying them to completely dry skin may reduce the likelihood of irritation. Freshly shaved, damp, or already irritated skin may be more sensitive. Because products differ in their ingredients and concentrations, how often they are used may vary depending on the person and the product.

Topical Medications

Certain prescription medications applied to the underarms aim to reduce the nerve signals that stimulate the sweat glands. In some countries, topical anticholinergic medications may be available in different forms, such as wipes, gels, creams, or solutions. Possible local or systemic side effects include:
  • skin irritation,
  • burning,
  • dryness,
  • dry mouth,
  • blurred vision,
  • dilation of the pupil if the medication comes into contact with the eye,
  • difficulty urinating
Because medications applied to the underarms can be carried to the area around the eyes by the hands, instructions for use and hand washing are important. The approved uses, age limits, and availability of these products may vary from country to country.

Oral Medications

Certain anticholinergic medications can be used systemically to reduce the nerve stimulation reaching the sweat glands. These medications can affect sweating not only in the underarms but also in other areas of the body. Possible side effects include:
  • dry mouth,
  • constipation,
  • blurred vision,
  • dry eyes,
  • difficulty urinating,
  • changes in heart rate,
  • drowsiness,
  • problems with concentration,
  • difficulty regulating body temperature
Sweating is one of the body's natural cooling mechanisms. For this reason, suppressing sweat production over large areas is a particular concern during hot weather, fever, or intense physical activity. Whether a medication is suitable is evaluated based on the person's age, health status, and other medications they take.

Is Botulinum Toxin Used for Underarm Sweating?

Botulinum toxin aims to temporarily reduce chemical signaling between certain nerve endings and the sweat glands. It is one of the treatment options used for primary axillary hyperhidrosis. During the procedure, many small injections are made into the skin of the area that sweats excessively. Its effect is not permanent. Sweating can increase again as nerve function is restored over time. Possible side effects include:
  • discomfort during the injections,
  • temporary tenderness,
  • bruising,
  • headache,
  • local irritation,
  • rarely, temporary weakness of nearby muscles
The duration of the effect can vary from person to person. The approved uses of botulinum toxin for hyperhidrosis may differ depending on the product and the country.

Is Iontophoresis Used for Underarm Sweating?

Iontophoresis is a method used mainly for hand and foot hyperhidrosis. Although some special devices have been developed for use in the underarm area, the procedure may be less practical than for the hands and feet because of the anatomy of the area and the sensitivity of the skin. Repeated initial treatments followed by maintenance sessions may be needed. Possible effects include:
  • dry skin,
  • redness,
  • burning,
  • irritation,
  • tingling
Suitability is evaluated separately during pregnancy and in people with certain implanted electronic medical devices.

What Localized Procedures Target the Underarm Sweat Glands?

Some procedures aim to directly reduce the number or activity of the sweat glands in the underarms. Different methods may use:
  • heat- or energy-based treatments,
  • mechanical reduction of the sweat glands,
  • curettage,
  • liposuction-like techniques,
  • limited surgical procedures
These methods differ in how they are performed, the level of scientific evidence supporting them, and their availability. Possible effects and complications include:
  • pain,
  • swelling,
  • bruising,
  • changes in skin sensation,
  • firmness under the skin,
  • infection,
  • scarring,
  • changes in skin color,
  • irregularity of the underarm skin,
  • insufficient reduction in sweating,
  • sweating increasing again over time
Because some localized procedures can cause permanent or long-lasting tissue changes, the potential benefits and complications are weighed together.

Is There a Role for Anxiety and Stress Management?

Because stress can increase axillary hyperhidrosis, psychological or behavioral approaches may be supportive for people with marked anxiety or avoidance behaviors. These may include:
  • relaxation techniques,
  • breathing exercises,
  • cognitive behavioral therapy,
  • evaluation of marked social anxiety,
  • reducing avoidance behaviors
These methods do not directly stop the sweat glands from working. The aim is to reduce the impact of the cycle in which anxiety increases sympathetic activity and the increased sweating in turn leads to new anxiety. Using psychological support does not mean that axillary hyperhidrosis is imaginary or purely emotional.

What Is the Role of Surgery in Underarm Sweating?

In isolated axillary hyperhidrosis, surgery is generally not considered a first-line treatment. Nonsurgical or local options are available, such as antiperspirants, topical medications, botulinum toxin, and various methods that directly target the underarm sweat glands. Thoracic sympathetic surgery, on the other hand, does not act on the sweat glands in the underarms directly, but on the sympathetic nerve pathways located inside the chest. The role of this surgery is more clearly established in severe primary palmar hyperhidrosis than in cases involving underarm sweating alone. For this reason, sympathetic surgery for underarm sweating is considered only in carefully selected cases in which appropriate less invasive methods have already been evaluated.

What Is ETS?

Endoscopic thoracic sympathetic surgery, commonly referred to as ETS, refers to surgical methods based on interrupting certain sympathetic nerve pathways inside the chest. These nerve pathways play a role in transmitting the signals that influence sweating. ETS can reduce sweating in some types of primary focal hyperhidrosis. However, when only the underarms are affected, results can be more variable than in severe primary hand sweating. For this reason, ETS is not considered a routine early-stage treatment for isolated axillary hyperhidrosis.

Is ETS Reversible?

Sympathetic nerve surgery should not be regarded as a reliably reversible procedure. In different surgical techniques, the sympathetic nerve pathway can be affected in different ways. Although some operations use surgical clips instead of physically cutting the nerve, removing the clip later does not necessarily mean that nerve function or the pre-operative sweating pattern will return. Nerve compression, scar tissue, and other permanent changes can occur. For this reason, sympathetic nerve surgery is evaluated with its possible long-term consequences in mind.

What Are the Possible Risks of Thoracic Sympathetic Surgery?

The use of a minimally invasive (closed) surgical technique does not mean that thoracic sympathetic surgery is risk-free. Possible outcomes and complications include:
  • compensatory sweating,
  • excessive dryness,
  • persistent underarm sweating,
  • recurrence of sweating,
  • different results on the two sides,
  • gustatory (taste-related) sweating,
  • pneumothorax,
  • hemothorax,
  • bleeding,
  • infection,
  • chest or nerve-related pain,
  • slowing of the heart rate,
  • Horner syndrome,
  • anesthesia-related complications
The likelihood of these risks can vary depending on the surgical technique, the extent of the procedure performed on the sympathetic nervous system, the person's anatomical features, and their general health.

What Is Compensatory Sweating?

Compensatory sweating is the appearance of new or increased sweating, after sympathetic surgery, in areas that previously sweated less. It is most often seen in areas such as the:
  • back,
  • chest,
  • abdomen,
  • lower back,
  • hips,
  • groin,
  • legs
Its severity can vary considerably from person to person. In some people it appears as slight dampness, while in others it can become intense enough to affect clothing and daily life. It may be more noticeable during hot weather, physical activity, or stress. There is no reliable test that can determine with certainty before surgery who will develop compensatory sweating or how severe it will be. No sympathetic surgery method completely eliminates this possibility.

Can Underarm Sweating Recur After Treatment?

The effects of many methods used for axillary hyperhidrosis are not permanent. When treatment is stopped or its effectiveness decreases over time, sweating can increase again. Sweating can also persist or return after a localized procedure or sympathetic surgery. Possible reasons for this include:
  • sweat glands that remain active,
  • individual anatomical differences,
  • differences in the method used,
  • changes in nerve conduction over time,
  • the presence of a secondary cause of sweating
Some physiological moisture in the underarms does not always mean that treatment has failed.

Why Is Follow-Up After Treatment Important?

Follow-up is not only about checking whether the underarms are completely dry. The following may also be considered:
  • changes in daily life,
  • the amount and distribution of sweating,
  • skin dryness or irritation,
  • body odor,
  • compensatory sweating after sympathetic surgery,
  • changes in sweating in other areas of the body,
  • recurrence of sweating,
  • the effects and side effects of medications being used,
  • social and psychological effects.
The effectiveness and tolerability of nonsurgical methods can change over time.

When Is a Medical Evaluation Important for Underarm Sweating?

Underarm sweating does not always indicate a disease. However, evaluating the cause of sweating becomes important when any of the following features are present:
  • Sudden onset of sweating
  • One underarm consistently sweating much more than the other
  • Heavy sweating during sleep at night
  • Sweating that affects the whole body
  • Accompanying fever, palpitations, shivering, or unexplained weight changes
  • Symptoms that appear after starting a new medication
  • Recurrent skin infections or marked irritation
  • Sweating that significantly affects daily life
  • If sudden sweating is accompanied by chest pain, shortness of breath, fainting, or other acute symptoms, urgent medical evaluation may be needed.

Frequently Asked Questions About Underarm Sweating

Why do my underarms sweat so much?
Underarm sweating can normally increase with hot weather, exercise, stress, and hormonal changes. Heavy sweating that recurs without an obvious trigger and affects daily life, however, may be related to primary axillary hyperhidrosis. Certain diseases and medications can also cause secondary excessive sweating.
Why do my underarms sweat even in the cold?
In primary axillary hyperhidrosis, the sweat glands can be overstimulated even in cool environments where the body does not need extra cooling. Stress and excitement can make symptoms worse, but primary hyperhidrosis cannot be explained by psychological causes alone.
How can underarm sweating be treated?
There is no single method that is right for everyone with axillary hyperhidrosis. Depending on the cause and severity of the sweating, antiperspirants, certain topical or oral medications, botulinum toxin, and localized methods targeting the underarm sweat glands may be considered. Thoracic sympathetic surgery is generally not a first-line option for isolated underarm sweating.
Are deodorant and antiperspirant the same thing?
No. A deodorant is mainly intended to reduce or mask body odor. An antiperspirant, on the other hand, reduces the amount of sweat reaching the skin surface by temporarily affecting the sweat ducts. Some products combine both properties.
Why do my underarms smell even after showering?
Underarm odor is not related to hygiene alone. Bacteria on the skin, apocrine gland secretions, and moisture in the area can all play a role in odor formation. Excessive sweating can make odor more noticeable, but sweating and odor are not the same condition. Persistent or unusual odors call for a separate evaluation of the skin and other possible causes.
Does botulinum toxin reduce underarm sweating?
Botulinum toxin can reduce sweat production in primary axillary hyperhidrosis by temporarily reducing the nerve signals that stimulate the sweat glands. Its effect is not permanent and may wear off over time. Whether the treatment is suitable is evaluated based on the person's clinical characteristics.
Does stress cause underarm sweating?
Stress and anxiety can increase sweating by stimulating the sympathetic nervous system. In people with primary axillary hyperhidrosis, this response may be more pronounced. However, the fact that stress increases sweating does not mean that hyperhidrosis is purely psychological.
Which doctor should I see for underarm sweating?
Localized axillary hyperhidrosis can be evaluated by dermatology. If sweating occurs over the whole body, continues at night, or appears together with other systemic symptoms, an evaluation by internal medicine, endocrinology, or another relevant specialty may be needed. A thoracic surgery evaluation is generally relevant in selected cases where sympathetic surgery is being considered.
Is excessive underarm sweating a sign of disease?
Not always. In primary axillary hyperhidrosis, no other disease may be found. However, sweating that is new, continues during sleep at night, or affects the whole body may be related to thyroid diseases, blood sugar changes, certain infections, hormonal conditions, neurological diseases, or certain medications.
Does compensatory sweating occur after ETS surgery?
After endoscopic thoracic sympathetic surgery, new or increased sweating can develop in different areas such as the back, chest, abdomen, lower back, groin, or legs. This is called compensatory sweating. Its severity varies from person to person, and there is no reliable test that can show with certainty before surgery who will develop it or to what degree.
Disclaimer: The information on this website has been prepared to inform the public about health topics. The content is not intended to provide a personal diagnosis, recommend a specific treatment, or replace a medical examination. Diagnostic and treatment approaches may vary depending on the person's clinical findings and general health. Please consult your physician about your personal health condition.