What Causes Diaphoresis?

Learn the causes of cold sweats

Diaphoresis is the medical term for cold sweats—sudden, whole-body sweating that doesn't come from heat or exertion. It can have many causes, ranging from typical life events to life-threatening medical emergencies.

This article looks at emergency symptoms related to diaphoresis, conditions that may lead to diaphoresis, why, and what to do about it.

causes of cold sweats

Verywell / Cindy Chung

Emergency Symptoms

Symptoms that accompany cold sweats and may indicate a medical emergency include:

  • Chest pain or pressure
  • Pain that radiates to the neck or arm
  • Cyanosis (blue lips or fingers)
  • Sudden rapid heartbeat or other heart rhythm changes
  • Weak pulse
  • Rapid breathing, labored breathing, or shortness of breath
  • Wheezing or coughing
  • No response to asthma medications
  • Pale skin
  • Weakness
  • Dizziness
  • High or very low temperature with chills
  • Cool, pale limbs
  • Lack of urine
  • Confusion or lethargy
  • Skin rash
  • New injury
  • Severe pain of unknown cause
  • Shaking
  • Anxiety or irritability

Call 911 if you or someone else has any of these symptoms.

Cold Sweats vs. Typical Sweat

Typical sweating is the body's way of cooling itself. It's triggered by heat from your environment or exertion that raises your body temperature.

The cold sweats of diaphoresis are unrelated to these causes. Sometimes causes of diaphoresis are emergencies, like septic shock or a heart attack, while others are less serious or not cause for concern.

Common causes of diaphoresis include:

  • Fight-or-flight response
  • Shock
  • Infection
  • Syncope (fainting)
  • Pain from injuries
  • Heart attack
  • Severe shortness of breath
  • Low blood glucose (sugar)
  • Fear and anxiety

Diaphoresis itself isn't a problem and it isn't treated directly. Instead, healthcare providers target the cause of cold sweats, such as treating an infection or providing pain management.

Paying attention to other symptoms you may have can help you determine what steps you need to take to protect your health.

Fight-or-Flight Response

Anything that causes a fight-or-flight response to stress in the body can cause cold sweats. This includes fear, phobias, and anxiety.

The fight-or-flight response is triggered when you encounter a situation your body sees as a threat. It allows you to either defend yourself or get away.

This is probably the most common cause of diaphoresis.


When fight-or-flight kicks in, your body dumps the stress hormones adrenaline and cortisol into your blood. Then:

  • Your blood pressure, heart rate, and breathing speed up.
  • Blood sugar rises to give you quick energy.
  • Your brain goes on high alert, paying attention to small details that it normally would filter out.
  • Your muscles are tense and ready to respond.
  • You have cold sweats.


When you're in fight-or-flight mode, the excess adrenaline in your system activates the sweat glands, causing diaphoresis.

What to Do: Give It Time

Once the cause of the fight-or-flight response is over, your body should return to normal after between 20 and 60 minutes. It may help to try calming your body through deep breathing or other relaxation methods.


Your body goes into shock when blood flow to the brain and other vital organs becomes dangerously low. That means the brain doesn't get enough oxygen and nutrients. Shock causes increasing body-wide stress.


Diaphoresis is a key symptom of this potentially life-threatening condition. Other symptoms include:

  • A sudden, rapid heartbeat
  • Weak pulse
  • Rapid breathing (more than 20 inhalations per minute)
  • Pale skin
  • Feeling weak or dizzy when sitting up or standing


Shock is often caused by an injury, such as a car accident or traumatic fall. Some injuries may produce obvious blood loss, but others involve internal bleeding that you can't see.

It can also be caused by:

These causes change the way your body handles blood flow. For example, infection and severe allergies affect the blood vessels in a way that significantly lowers blood pressure.

What to Do: Call 911

Shock is serious enough to warrant immediate medical attention. Call 911 for help if you suspect you or someone else is in shock.

Until help arrives, lie flat on your back with your feet propped on something about 8 to 12 inches tall. That helps preserve blood flow to the brain and vital organs.


The flu, COVID-19, and any other infection that causes a fever can lead to cold sweats. Sometimes they occur as a fever "breaks" or starts to go back down.

In severe cases, the body may go into septic shock.


Common symptoms of infection include:

  • Fever
  • Chills and cold sweats
  • Cough
  • Sore throat
  • Shortness of breath
  • Nasal congestion
  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Discoloration, pain, or swelling around wounds

Symptoms of septic shock may be:

  • High or very low temperature with chills and cold sweats
  • Cool, pale limbs
  • Lightheadedness
  • Little or no urine
  • Low blood pressure that may cause dizziness when standing
  • Heart palpitations
  • Restlessness, agitation, confusion, or lethargy
  • Shortness of breath
  • Skin rash or discoloration


Medical conditions that can lead to septic shock include:

Septic shock is most common in the very old, the very young, and people with a compromised immune system.

What to Do: Call 911 or Make an Appointment

Septic shock is always a medical emergency. It often requires time in an intensive care unit. If you suspect septic shock, call 911 or get to an emergency room right away.

For an infection that causes cold sweats but not septic shock, make an appointment to see your healthcare provider soon or go to an urgent care facility. Be sure to stay hydrated, especially if you're sweating heavily and/or have a fever, vomiting, or diarrhea.

Diaphoresis vs Hyperhidrosis

Diaphoresis and hyperhidrosis aren't the same. Diaphoresis is a symptom of many conditions while hyperhidrosis is a medical condition that involves excessive and unpredictable sweating. It's believed to be caused by overactive sweat glands.


Cold sweats may be a symptom of syncope, often called fainting or passing out.


When you have syncope, you briefly lose consciousness. This typically makes you fall to the ground (or slump, if you're sitting).

Before you pass out, you may have symptoms of pre-syncope (the feeling you're about to faint). These can include:

  • Lightheadedness
  • Nausea
  • "Grayed out" vision
  • Trouble hearing
  • Heart palpitations
  • Weakness
  • Diaphoresis

With syncope, you may also experience:


Syncope is caused by a sudden drop in blood pressure. This can be caused by:

  • Slow, fast, or irregular heartbeats (arrhythmia)
  • Low blood pressure, often after standing up

Those changes in heart function and blood flow may be the result of:

What to Do: Get Medical Attention

If you've had syncope or pre-syncope for an unknown reason or due to trauma or a medical event, get medical attention right away.

Fainting can lead to serious injuries. Get medical help for someone who gets hurt during an episode of syncope.

If the reason for syncope is known and not serious (such as an emotional shock), lying on the back with the feet elevated can help.

You should always let your healthcare provider know if you've had syncope or pre-syncope.

Night Sweats

Night sweats are a type of diaphoresis that may be tied to:

Severe Pain

Severe pain from an injury, like a fracture or non-surgical amputation (losing a body part), can lead to cold sweats. Some medical causes of severe pain, such as kidney stones, can also cause diaphoresis.


The only consistent symptoms in this case are severe pain and cold sweats. Other symptoms will vary depending on what's causing the pain.

In rare cases, severe pain can occur long after a head injury or spinal cord trauma. This is a symptom of complex regional pain syndrome (CRPS), and diaphoresis is a common feature.

Other symptoms of CRPS include:

  • Severe burning or aching pain
  • Pain that increases with even a light touch
  • Skin temperature fluctuating between hot and cold
  • Rapid hair and nail growth
  • Muscle spasms
  • Joint pain
  • Skin that appears pale, discolored or mottled, thin, and shiny


The cause of diaphoresis in severe pain is similar to that of shock.

CRPS may be caused by a problem with the immune system that leads to problems with nerves that control flood flow, temperature, and sensation.

What to Do: Call 911 or Make an Appointment

For a new serious injury or undiagnosed medical cause of severe pain, call 911. Once the severe pain is treated, cold sweats and other symptoms should diminish.

If you suspect you may have CRPS, make an appointment with your healthcare provider.

If the pain is from a diagnosed cause that isn't an emergency (such as cancer, a chronic pain condition, or a healing injury), treat your pain as directed by your healthcare provider. If you don't have the means to treat your pain, make an appointment to discuss pain management.

Heart Attacks

Cold sweats are a common sign of a heart attack (myocardial infarction).


Aside from diaphoresis, symptoms of a heart attack may include:

  • Chest pain or pressure
  • Pain that radiates (spreads) to the neck or arm
  • Shortness of breath
  • Nausea
  • Vomiting
  • Dizziness
  • Cyanosis (a blue tint to the lips or fingers)
  • Changes to your heart rhythm


In a heart attack, blood flow to your heart muscle is interrupted. This triggers a stress response that leads to diaphoresis.

What to Do: Call 911

A heart attack is a true emergency. Call 911 immediately. The faster that you act, the better your chances of limiting damage and having a better outcome.

Taking a chewable aspirin while waiting for the ambulance may help prevent heart damage.

Shortness of Breath

Severe shortness of breath can lead to diaphoresis, among other symptoms.


Other signs of shortness of breath may include:

  • Rapid breathing
  • Pursed-lip or tripod (leaned forward) breathing
  • Mental confusion
  • Wheezing or coughing
  • Fatigue
  • Anxiety


When you're short of breath, it causes a lack of oxygen in the bloodstream. When your brain begins to crave oxygen, it sends your body into a stress response, similar to fight-or-flight or shock.

What to Do: Call 911 or Treat Your Shortness of Breath

Any time you have trouble breathing, it's a serious situation. Call 911 if:

  • You don't know the cause
  • Have a known cause that's an emergency (such as anaphylactic shock or a lung injury)
  • Can't quickly get yourself breathing better

If you have shortness of breath due to a known condition, such as asthma or chronic obstructive pulmonary disorder (COPD), follow your healthcare provider's instructions. If your usual treatments don't work, call 911.

Low Blood Glucose

Hypoglycemia (low blood glucose/sugar) is a fairly common reason for cold sweats. It's seen most often in people with diabetes or prediabetes.


Other common symptoms of hypoglycemia include:

  • Rapid heartbeat
  • Shaking
  • Nervousness or anxiety
  • Irritability or confusion
  • Dizziness
  • Hunger


Glucose is the brain's preferred source of energy, so it responds to low blood sugar as a serious threat. As with a lack of oxygen, this triggers a stress response that leads to diaphoresis.

What to Do: Call 911 or Make an Appointment

If someone with diabetes seems confused or has other symptoms of hypoglycemia, call 911 and get them something sugary to eat or drink.

If you have symptoms of hypoglycemia but aren't diagnosed with a condition that can cause it, make an appointment with your healthcare provider.


Many types of cancer can cause diaphoresis, especially at night. They include:


Early cancer symptoms can vary greatly depending on the type, location, and stage of the tumor(s). Some common early symptoms may include:

  • Fatigue that doesn't improve with rest
  • Unintended weight loss of more than 10 pounds
  • Loss of appetite
  • Trouble swallowing
  • Abdominal pain, nausea, and vomiting
  • Unexplained swelling
  • Lumps anywhere in the body
  • Breast lumps or thickening tissues
  • Pain with no known cause that doesn't go away or gets worse
  • Changing moles
  • Sores that don't heal
  • Skin lumps that bleed or scale
  • Jaundice (yellowing skin or eyes)
  • Ongoing cough or hoarseness
  • Unusual bleeding or bruising
  • Changes in bowel habits (e.g., diarrhea, constipation)
  • Abnormal appearing stools
  • Pain when urinating, bloody urine, or frequent urination
  • Headaches
  • Vision or hearing problems
  • Mouth sores, bleeding, pain, or numbness


In some cases, cancerous tumors trigger changes in the body that lead to diaphoresis.

Some cancer treatments—including chemotherapy, radiation, hormone treatments, and some other medications—can also cause excessive sweating. So can morphine, which is sometimes used to treat cancer pain.

Common problems associated with cancer that can cause cold sweats include:

  • Infections
  • Menopause (triggered by surgery or hormone therapy)
  • Severe pain
  • Poor mental health (anxiety, depression)
  • Trouble sleeping
  • Testicle removal (a common treatment for prostate cancer)

What to Do: Make an Appointment

While cancer is a serious and potentially life-threatening illness, it's not something you generally need emergency treatment for—especially if you're just noticing what could be early symptoms.

If you're having concerning symptoms, make an appointment with your healthcare provider. Explain your symptoms and concerns and stress that you need to be seen soon. Early diagnosis can make for a better outcome.

Similar to menopause, hormonal changes from breast cancer or breast cancer treatment may cause hot flashes and heavy sweating. Why sex hormone changes have this effect isn't yet understood.


Cold sweats are different from sweat in response to heat or exertion. They're called diaphoresis and they have many causes, such as a fight-or-flight response, low blood sugar, or life-threatening events like a heart attack or shock.

Mechanisms that cause of diaphoresis include the body's response to stress, loss of blood, low blood pressure, and adrenaline directly stimulating the sweat glands.

Emergency causes warrant a call to 911. For others, you may want to see your healthcare provider. Some causes, such as fight-or-flight, should go away quickly on their own.

Frequently Asked Questions

  • Why do I wake up in a cold sweat?

    So-called “night sweats” can be caused by the same conditions that bring on other cold sweats. Other possible causes include hormonal changes, depression, thyroid disease, or medication side effects.

  • Are cold sweats normal during drug withdrawal?

    Yes, especially during opiate and alcohol withdrawal. In severe cases, people need to be carefully monitored for life-threatening complications of drug withdrawal.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.