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No Sweat, Colored Sweat, Bloody Sweat, Smelly Sweat, & Extreme Sweat

Typically, we’re sharing information and support related to hyperhidrosis (excessive sweating). But along the way, and because we’re founded and directed by expert dermatologists who treat the full range of skin-related disorders, we’ve learned A LOT about other types of sweat issues, too. 

Key take-away? Sweat is essential to human survival, but when sweating takes on different manifestations, other serious issues come up, too -- like lack of awareness and understanding, embarrassment, shame, fear, and more. 

While most of the conditions listed below are quite rare, rare is still real and we really want to be here for you no matter what your sweat problem may be. So let’s learn more, listen more, and help each other more. Starting now.


Anhidrosis = No Sweat

No sweat? No, it’s not really a dream come true. For the hyperhidrosis sufferer, the inability to sweat might seem like a blessing. But, actually, if you can’t sweat, a whole host of other problems can arise. In extreme cases, anhidrosis (the inability to sweat) can even be life-threatening. 

Anhidrosis is defined as the absence of sweating. It can affect small or large areas of the body and be caused by one or more of dozens of factors. No one knows exactly how many people are affected by anhidrosis. That's probably because people with mild cases may not even be aware that they have the condition, or, if they are, they may never report it to their healthcare providers

Sweat is essential to human survival because it serves as the body's coolant, getting rid of excess body heat (produced by your metabolism and working muscles) and protecting you from overheating. 

Whenever your body temperature begins to increase, your autonomic nervous system stimulates your sweat glands (the average person has 2.6 million of them) to secrete fluid onto the surface of your skin. As this fluid (called perspiration or sweat) evaporates, your body starts to cool down. Under normal circumstances, a single pea-sized bead of sweat can cool nearly 1 liter (about 1 quart) of blood by 1 degree Fahrenheit. 

Because they can't sweat (or can’t sweat enough) and, therefore, can't cool their bodies, people with severe anhidrosis have trouble working and exercising in heat and can be in serious danger if they attempt strenuous activity in high temperatures. Without being able to sweat, they are at high risk for heat-related illnesses such as heat exhaustion and heat stroke. In extreme cases, or if these heat-related illnesses are not treated appropriately, coma or death can result. 

Poor sweating can occur as an isolated condition or as part of a group of symptoms associated with another disease. It can also occur after skin has been injured, because sweat glands are clogged or obstructed, as an inherited defect, or as a side effect of a medication (by the way, medications can also cause excessive sweating - check out our list of potential culprits). 

Given the wide range of reasons why a person may not be able to sweat, it's often difficult to pinpoint the true origin of the condition in an individual. For people who suffer from anhidrosis on only small parts of their bodies, treatment is probably not necessary because sweat from other body areas can usually compensate and keep the body cool. But for those with large body areas affected, finding the cause of the problem is often crucial to finding a treatment. 

Factors that may lead to anhidrosis include (but are not limited to):

  • Certain Drugs/Medications: In particular, antipsychotic medications used to treat serious mental disorders may interfere with normal functioning of the sweat glands. Also, medications with anticholinergic properties and calcium-channel blockers may cause anhidrosis. (Side note: for hyperhidrosis sufferers who take oral medications to control their sweating, anhidrosis and heat-related issues can be a concern and we encourage you to learn more.)
  • An Inherited Condition: It's rare, but some people are born without sweat glands. For example, ectodermal dysplasia is a condition that impacts the development of the skin, sweat glands, nails, teeth, and/or mucous membranes. Without sweat glands, there’s a high risk of overheating (hyperthermia), especially in hot environments.

  • Nerve Damage: Injuries to the nerves that help control some of the involuntary functions of the autonomic nervous system (which regulates your internal organs, sweat glands, and blood pressure, for instance) can interfere with the activity of your sweat glands. Such nerve damage may be caused by a number of medical problems including gout, B-vitamin deficiency, diabetes, and alcoholism. (On the other side of the spectrum, nerve damage can also cause unwanted excessive sweating. Frey’s syndrome (gustatory sweating) is extreme sweating that occurs with eating and it’s related to surgery or trauma to a parotid gland.)

  • Clogged Ducts: Skin diseases and conditions that can block or clog sweat ducts (a problem called poral occlusion) are the most common causes of anhidrosis. This is, by the way, how antiperspirants work, albeit on a localized, desired and temporary basis.

  • Skin Injures: Injuries to the skin and sweat glands can also cause anhidrosis. Such injuries can occur due to major third-degree burns from fire, chemicals or electricity, or from medication overdose or poisonings.

  • Dehydration: This occurs when you don't have enough water in your body to carry on normal functions. You can easily become dehydrated when you work or exercise in hot weather and don't drink enough fluids to replace what you've lost through perspiration. Other common causes of dehydration include persistent vomiting or diarrhea or the use of medications that increase the flow of urine (diuretics). If these problems last long enough, a person can eventually lose so much fluid that he or she is no longer able to sweat. Signs and symptoms of dehydration include thirst, weakness, and confusion. Severe dehydration can be fatal, particularly in older adults and children.

  • Heat Stroke: Like dehydration, heat stroke can occur when you work or exercise strenuously in hot weather and don't drink enough to replace the fluids you've lost. Heat stroke is serious because it causes your body's normal mechanisms for dealing with heat stress to shut down. Major signs of heat stroke are a high body temperature (generally greater than 104 degrees Fahrenheit / 40 degrees Celsius) with hot, dry skin (no sweating), confusion, and even coma. Heat stroke can be fatal.

Treatment for anhidrosis depends on the cause and, unfortunately, many cases aren’t easily treated. If you develop a noticeable decrease in sweating, it's important to talk to a healthcare professional and discuss any medications you are taking (a plea to hyperhidrosis sufferers, please take your medication only as directed by your physician and tell him/her about any side effects). Anhidrosis of a limited body area is usually not a problem, but anhidrosis over large portions of the body can dangerously limit your ability to keep cool. In such instances it's important to take steps to prevent heat exhaustion, heat stroke, and dehydration until you can discuss your anhidrosis problem with a healthcare professional.

Bromhidrosis = Bad Body Odor

Humans have two types of sweat glands: eccrine and apocrine. Eccrine sweat glands are found in large numbers on the soles of the feet, palms, forehead, cheeks, and in the armpits. These glands produce a lot of watery, usually odorless sweat. Hyperhidrosis, or excessive sweating, is typically due to eccrine gland activity. 

Excessive bromhidrosis (extreme body odor, unpleasant smelling sweat, or osmidrosis), however, is usually due to over-eager apocrine glands. Apocrine glands are primarily located in the armpits and genital region. They produce a thicker, more viscous sweat. When this type of sweat comes in contact with bacteria on the skin's surface, it can cause that tell-tale, potent, “body odor” smell. Fun fact: there seems to be a connection between underarm odor and the stickiness of a person’s ear wax, but DON’T go sticking deodorant in your ears, please. 

Truth be told, we all get smelly sometimes and that’s normal. But bromhidrosis becomes a medical issue when noticeable smell has a negative effect on your self-esteem, social interactions or quality of life. If your body odor is having unwanted impacts on your life, don’t delay -- help yourself and get professional help as needed. 

  1. Keep the body area in question dry. Antiperspirants, powders and frequent clothing changes can help with this. (Women, however, may want to learn more about potential risks of long-term use of talc-based powders in the genital region.)
  2. Wash smelly parts regularly with an antibacterial soap. 
  3. Consider safe shaving, waxing or electrolysis of fuzzy spots that are also sites of odor. Hair can magnify odor.
  4. Use a deodorant. Most antiperspirants are also deodorants. Just read the labels to make sure your product has you covered in all the right places.
  5. Look at your diet. Try limiting curry, garlic, onions, and alcohol. Medications can sometimes also cause bromhidrosis. Penicillin is one example of a potentially smelly Rx. Of course, NEVER stop taking any medications without consulting your prescribing physician first! But do discuss body smell concerns with your provider. Perhaps a change in medication will avert this side effect. 
  6. Still stinky? Talk to your dermatologist or another medical professional. miraDry and Botox injections are both treatment options for bromhidrosis. 

We hope you can soon say bye-bye to too much stink.

Chromhidrosis = Colorful Sweat

Chromhidrosis is a disorder of the sweat glands that manifests with colored sweat on the face, in the underarms, or on the areola of the breasts (the darker circle of skin around the nipples). Sweat may be yellow, green, blue, brown, or black. The colors are due to a pigment produced in the sweat glands called lipofuscin. Lipofuscin is common in human cells, but for some reason people with chromhidrosis have higher concentrations of lipofuscin or lipofuscin that is in a higher-than-normal state of oxidation. Some people with chromhidrosis may report a feeling of warmth or a prickly sensation before the onset of colored sweat. 

The condition is quite rare and there aren’t really statistics on how many people are affected by it. It seems, however, to be more common among those with African heritage. 

A more frequent type of discolored sweat is called pseudochromhidrosis. With pseudochromhidrosis, sweat takes on an unusual color after secretion from the sweat gland as it comes in contact with dyes, chemicals, or chromogenic bacteria on the skin (bacteria that produce pigments.)

Other possible reasons for the appearance of colored sweat include: infection, blood in the sweat (hematidrosis, see below), excess bilirubin (an orange-yellow pigment formed in the liver), and/or poisoning. 

If you experience sweating in an unusual hue, talk to your healthcare provider. He or she will likely want to take the necessary steps to rule out potentially more serious medical conditions before making a diagnosis of chromhidrosis.

According to the medical journal Pediatrics, chromhidrosis can be treated with topical capsaicin cream 0.025% (applied to the affected skin 1-2 times per day). Others have noted that Botox injections can treat chromhidrosis. Either way, because the condition is chronic, treatment will need to be maintained for continuous results. (As always, talk to your healthcare provider about your individual situation to receive an accurate diagnosis before beginning any treatment.)

The goal of treatment for chromhidrosis is to reduce symptoms in order to also reduce any related psychosocial impacts or stigma. Similar to what can happen with other sweat disorders listed in this blog, chromhidrosis can lead to embarrassment, sadness, anxiety, and feelings of social isolation. Finding understanding, treatment and support is so important with any skin disorder!

Hematidrosis = Sweating Blood

Hematidrosis or hematohidrosis is perhaps the most unusual condition we’ll talk about today. It’s an extremely rare problem (only a handful of cases have ever been reported) that causes a person to sweat blood, often on the face or forehead, without being cut or injured. Symptoms appear as blood droplets on the skin, bloody sweat or sweat with blood in it. 

One theory behind hematidrosis is that it’s linked to the body’s “fight or flight” response; triggered by extreme fear, stress or physical exertion. The thought is that during high stress, tiny blood vessels in the body (capillaries) can rupture causing blood to seep into the sweat glands and then out onto the skin. In other cases, hematidrosis may be a symptom of a medical condition like high blood pressure. 

If you ever experience bloody sweat, definitely tell your doctor. While hematidrosis is likely not serious, your doctor will likely want to run tests, try to find the cause, and make sure you’re a-ok. If stress is a potential trigger, addressing life situations will be important. For an ongoing hematidrosis problem, blood pressure medications, antidepressants, anti-anxiety medications, or meds that help control bleeding might be considered. Anxiety caused by seeing blood on the skin and related social stigma are situations that likely also need to be addressed to help a hematidrosis sufferer. Again, this condition is, thankfully, very, very rare. 

Hyperhidrosis = Excessive Sweating

In people who have hyperhidrosis (Hh or excessive, chronic, uncontrollable sweating), sweat glands overreact to stimuli or are generally overactive; producing more sweat than is necessary or considered “normal” as a reaction to temperature, exertion, stress, or simply living. No one really knows why this happens but experts often say that people with hyperhidrosis have sweat glands that are stuck in the "on" position -- so much so that they may sweat four or five times more than other people. 

As the International Hyperhidrosis Society, we could go on all day with statistics and information about hyperhidrosis (check out our Hyperhidrosis 101 podcast!) But for now, here are a few of the important things everyone should know about it:

  • 4.8% of the population is affected by Hh (that’s ~365 million people worldwide).
  • The above makes Hh more common than autism, melanoma, psoriasis & peanut allergies.
  • Depression and anxiety are more than twice as common among Hh sufferers. Risk of skin infections is tripled with Hh.
  • Hh negatively impacts functionality and satisfaction at school, at work, in sports, during hobbies, and so much more. Indeed, some experts argue that Hh is perhaps the only chronic skin condition that directly affects people’s abilities to DO things (like open jars and door knobs.)
  • Social relationships can also be harmed by Hh along with social-emotional wellness and intimacy. 

Another key point is that there are two types of hyperhidrosis: primary vs. secondary. Secondary Hh is sweating that is caused by or is a symptom of another underlying medical condition or is a side effect of a medication a person is taking. Ruling out secondary hyperhidrosis (or responding to secondary Hh appropriately) is a crucial step in Hh management and good health because secondary Hh can be a symptom of other serious medical issues that need care, too. If secondary Hh has been ruled out, healthcare providers solidify diagnosis of primary (or idiopathic) Hh by considering the following: 

A: Age of onset

Hh often begins during childhood or adolescence (with facial sweating onset trending later). 

B: Bilateral

Hh sufferers typically experience bilateral (on both sides of the body), symmetric involvement of palms, feet, face/scalp and/or underarms (or other specific body areas or body area combinations). Bilateral means, for example, that both feet, both hands, both underarms and/or both sides of the face experience extreme sweating at the same time.

C: Cessation during sleep

People with primary hyperhidrosis usually do not sweat excessively during sleep

D: Duration

To be considered hypehidrosis -- disruptive, extreme sweating episodes typically need to have been occurring consistently for the past few months; doctors often use 2 or more episodes per week for the past 6+ months as an instructive timeline. 

E: Episodes

Extreme, uncontrollable sweating will likely not be constant. Most sufferers will experience “episodes” of varying length/degree. These episodes are not related to the weather, to hot conditions, to exercise, or to stressful conditions.

F: Family

2/3rds of Hh sufferers indicate other family members have Hh, too. 

G: Gets in the way

Some level of sweating and increased sweating is to be expected in life. But Hh gets in the way of sufferers’ abilities to function, work, have fun, pursue dreams, develop relationships, and more.

Fortunately, there are treatment options to help hyperhidrosis sufferers better control their symptoms. We’ve got detailed information about all the current Hh treatment options available. Just check out each treatment’s page using the links provided below: 

  • Antiperspirants - Used on the skin, available in a range of strengths, may be used on multiple body areas. Learn proper application for maximum efficacy without irritation.
  • Iontophoresis - Often used for hands and/or feet. Home-use medical devices available. Non-invasive. Consistent schedule and how-to training required. 
  • Injections (Botox) - Can provide months of relief from sweating severity. Frequently used for underarms and face/scalp. May also be used for hands, feet, back, groin, and other distinct areas. “Touch ups” may be needed if areas are missed.
  • Microwave thermolysis (miraDry)  - In-office procedure that uses a handheld device (miraDry) to destroy sweat glands. Effects should be permanent. Lasers may also be used for this purpose. Only for underarms. 
  • Topical anticholinergics (Qbrexza) - Applied to the skin of the underarms. Prescription medicine applied to the skin that utilizes anticholinergic properties on the impacted areas. 
  • Oral anticholinergics - Best used for generalized sweating or sufferers who have tried other options without success. May be used periodically to prevent embarrassing sweating at important events (weddings, presentations, etc.) Learn about potential side effects. 
  • Surgical techniques - There are various underarm procedures that may be considered. Endoscopic thoracic sympathectomy (ETS) surgery is only recommended as a last resort for excessive hand sweating. Become fully informed of the risks of compensatory sweating with ETS.

As you learn more about all the above options, please keep in mind that hyperhidrosis care is not “one size fits all.” Treatments may require adjustments and combinations to meet your needs. Working with a caring, hyperhidrosis-savvy healthcare provider is very helpful. Search for one using our Physician Finder

Our Hidrosis Family

Each “hidrosis” we’ve covered here has so much in common with hyperhidrosis: lack of awareness and understanding, embarrassment, anxiety, and perhaps feeling the need to “hide” or “cover up” what’s going on. We hope that by getting all of these conditions more out in the open we can help sufferers to find ways to manage symptoms and feel better physically, socially and emotionally. We also hope that more healthcare providers will stay up-to-date on best practices in the full range of sweat-related diagnosis and care. 

No matter your sweat issue, we welcome you into this community and are here to help! Check out our videos, podcasts, past blogs, and whole website to stay on top of sweat-related news, research, and events. You can also connect with us on social media:

Facebook @SweatingStopsHere

Twitter @WeKnowSweat 

Instagram @WeKnowSweat



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