Sweating: the neglected cardiac symptom

by Carolyn Thomas  ♥ @HeartSisters

One of the first heart attack symptoms I experienced (along with central chest pain, nausea and pain down my left arm) was profuse sweating. I was out for my regular early morning walk at the time, but not going faster than usual or trekking up a steep hill. It was a mild spring day – just your average Monday morning walk along the relatively flat streets of my neighbourhood.

As a former distance runner, I have had years of experience on long very sweaty runs. But sudden sweating during an easy flat walk? That just doesn’t happen to me.       .

Sweating (or what doctors like to call “diaphoresis”  to show they’ve been to medical school) can be a significant cardiac warning sign, especially if it feels “unusual”. In fact, the top three most commonly reported cardiac symptoms in both women and men are chest pain, sweating and shortness of breath.(1)  Chest discomfort (sometimes but not always described as “pain” by women) is the most common warning sign of myocardial infarction (heart attack), reported by about 80 per cent of both women and men during a heart attack.   See also: What is Causing My Chest Pain?

Dr. Catherine J. Ryan is the Director of Nursing Research at the University of Illinois in Chicago. She and her team studied these 12 heart attack symptoms  – including sweating – reported by over 1,000 heart attack survivors:

  • chest discomfort/pain
  • shoulder, arm, or hand discomfort
  • sweating
  • neck or jaw discomfort
  • shortness of breath
  • back discomfort
  • abdominal discomfort
  • indigestion
  • nausea/vomiting
  • dizziness/light-headedness
  • weakness
  • extreme fatigue

She reminds us that “breaking out into a sweat for no apparent reason is one thing that you can’t explain away” – as we often try to do with other cardiac symptoms at first – like shortness of breath (out of shape?), nausea (something I ate?), fatigue (all women are tired!), and even chest pain (a pulled muscle?)   See also: Denial and its Deadly Role in Surviving a Heart Attack

As Dr. Ryan warned:

“Warning bells should ring off if a person suddenly starts sweating profusely.”

Historically, cardiologists have called any symptom that isn’t typical of a male heart problem (e.g. many of those 12 symptoms on Dr. Ryan’s list) “atypical”.  But given that women make up over half the population, our cardiac symptoms can only be described as “atypical” if you somehow believe that all cardiac symptoms should be defined exclusively by male assessment standards.

Dutch researchers, for example, observed in 2020 that women with acute coronary syndrome (ACS, the dangerous precursor to a heart attack) may indeed report different symptoms than men with ACS, but there is also considerable overlap.1  They warned:

“Since these differences have been shown for years, cardiac symptoms should no longer be labeled as atypical or typical.”

Dr. Ryan also tells us that if we don’t pay closer attention – especially to a “cluster” of symptoms happening at the same time –  it almost always means that we will delay seeking timely treatment – which, not surprisingly, can worsen our outcomes during a heart attack.  Her study found that the more of these “cluster symptoms” we experience, the shorter our treatment-seeking delay behaviour will be.

In other words, we know that women tend to ignore or minimize one or two of their earliest cardiac symptoms, but it’s much harder to ignore a whole bunch. And unusual sweating – whether profuse sweating that doesn’t match the level of physical exertion or cold/clammy sweats – can be one of those symptoms we should not ignore.  See also: Denial and its Deadly Role in Surviving a Heart Attack

That “shorter”  delay time, by the way, still averaged a whopping 9.7 hours before the heart patients followed in this study decided to finally seek emergency help.

IMPORTANT NOTE:  You know your body. You KNOW when something is just not right. Ask yourself what you’d do if the same symptoms were happening to your Mum, or your daughter, or your sister – and take the same quick actions for yourself.

Other studies suggest that sweating isn’t limited to heart attack symptoms.  Italian researchers, for example, called sweating the neglected sign in heart failure patients.” 2   See also: Is it Finally Time to Change the Name ‘Heart FAILURE’?

Sweat evaporation from the skin surface is a pretty important bodily function. It’s your body’s natural cooling mechanism. In people who don’t or can’t adequately sweat, body core temperature can rise sharply with exercise or heat stress, which can lead to heat exhaustion or heat stroke unless other life-saving means of cooling are available.3

Heavy night sweats or clammy sweats can also be a cardiac symptom, but many women may mistake these as a common menopause issue.  If you wake up to find the bed sheets are soaked through, or if you can’t sleep due to sweating, talk to your doctor.

Why does a cardiac event often cause unusual sweating?

In blocked coronary arteries, it takes more effort for your heart to pump oxygenated blood to the heart muscle, so your body sweats more to try to keep your body temperature down during that extra effort.  And as the Italian researchers explained, in patients diagnosed with heart failure, their overactive sympathetic nervous system can “generate a signal to the sweat glands to increase the  dispersion of fluids.”  

If you’ve ever been sick with a high fever, you know that sweating can accompany an abnormally high body temperature.  Fever can also arise in patients during an acute heart attack. These fevers can peak as early as 4-8 hours after the onset of a heart attack and usually come back down by the fourth to fifth day.4  Post-infarct fever has been recognized as a response to significant heart muscle damage.

Remember: never try to explain away unusual sweating if it accompanies chest discomfort.  Seek immediate medical help.

  1. Roos E. M. van Oosterhout et al. “Sex Differences in Symptom Presentation in Acute Coronary Syndromes”, Journal of the American Heart Association, 2020.
  2. Slavich M. et al. “Hyperhidrosis: the Neglected Sign in Heart Failure Patients”. Am J Cardiovasc Dis. 2021 Oct 25;11(5):635-641
  3. Taylor NA. “Human Heat Adaptation”. Compr Physiol. 2014;4(1):325–365
  4. Lofmark R. et al,  “The Temperature Course in Acute Myocardial Infarction.” American Heart Journal; 96:153–156.
Image: Arul, Pixabay

Q:  Was unusual sweating one of your own cardiac symptoms?

ANOTHER NOTE FROM CAROLYN:   I wrote more on common (and uncommon) cardiac symptoms in female heart patients in my book, A Woman’s Guide to Living With Heart Disease (Johns Hopkins University Press), you can ask for it at your local bookshop, or order it online (paperback, hardcover or e-book) at Amazon –  or order it directly from my publisher, Johns Hopkins University Press (use their code HTWN to save 30% off the list price).

22 thoughts on “Sweating: the neglected cardiac symptom

  1. Pingback: RN in NYC
  2. Hello Carolyn, finally a sweat connection! Thank you.

    I went through menopause 17 yrs ago and had short lived symptoms. However, about 10 yrs ago I started having significant night sweats – the get up, towel dry , change the bed, change PJs night sweats.

    I figured there had to be a connection to my coronary microvascular disease, and now I have an answer.

    I get minor ones during the day as well. I also appreciated the confirmation of why I struggle so much with the heat now. I did know the physiology of it, but it is nice to have the reminder.

    I don’t do hot tubs or saunas and it seems like I can tolerate less and less heat. I had a couple of very uncomfortable, verging on worrying, episodes in high temps and I am pretty conscious about avoiding those situations.

    Always appreciate the “hard” information I get from your posts!

    Liked by 1 person

    1. Oh my, Lauren – those “get up, towel dry, change the bed, change PJs” night sweats sound exhausting. You know that something in your body is out of whack when you are suffering those kinds of symptoms. I’m wondering what your doctor said about these night sweats, or if you’ve had thyroid tests done?

      Many heart patients tend to suffer during the heat – far more than those who don’t live with a cardiac diagnosis. I wrote more here: “This Is Your Heart In Hot Weather” And if the humidity is also high, sweat can’t readily evaporate from the skin – which pushes body temperatures even higher (a perfect setting for heat stroke).

      Hot tubs and saunas? Like you, I can’t even imagine voluntarily subjecting my body to that kind of full force heat.

      For the past few years, we’ve seen alarming increases in dangerous summer heat waves, even here on the balmy west coast. In the summer of 2021, over 600 deaths occurred here in B.C. due to our extreme “heat dome” conditions – high temperatures are a very real health threat. Most of those deaths happened to people over 70 who were indoors.

      So far, I’ve added ceiling fans and sun-blocking draperies to my home – and every flat surface seems to have a table fan going all summer. I’m saving up for a small air conditioner next for this coming summer!

      Meanwhile, take care and stay safe. . . ♥


  3. Love this. After being angina-free for a long time, I had 2 events. The second one I had the cold sweats, lots of pressure under my ribs. Pain in left arm from shoulder to hand. Neck and jaw pain. I was afraid to move.

    Took nitro and then another to be able to breathe. Since November I have been having tests. I have severe arrhythmia, then I was sent to a pulmonologist for spirometry.

    She says I have asthma although I’m not wheezing or coughing. Back to cardiologist, the Holter monitor shows crazy arrhythmia, 9000 events in 24 hours. Stress test short of breath, but could do 3 minutes.

    He thinks it’s my lungs. She says heart. I was diagnosed 12 years ago after an angiogram showed that arteries were clear and diagnosed with microvasular disease.

    I really am pushing for a quality of life! Just keep getting worse. I’ll see cardio again soon, he upped the dose of arrhythmia meds to 2 pills a day.

    Liked by 1 person

    1. Hi Lynn – you are going through such a frustrating scenario: dueling doctors! One says one thing, the other something different, and tests don’t seem to be pointing to one specific cause. You are a challenge for these two! I’m not a physician so cannot comment specifically on your experience, except generally that very severe asthma can sometimes cause abnormalities in Holter monitor readings.

      I’m sorry you’re suffering distressing symptoms. A good quality of life is really the best we hope for – even when we live with symptoms. Please keep pushing for answers, even though I know it’s hard to keep doing that. I wish you good luck and best of all, some positive answers when you see your cardiologist again.

      Take care, stay safe. . . ♥


  4. Thanks for sharing this Carolyn!

    In the 6 months or so leading up to my heart attack, I did indeed have unexplained sweating from time to time.

    I remember one day I was out in the garden and had been doing some light pruning for a very short period of time and I was sweating as though I had been running. At the time, I thought it was odd but explained it away as somehow being out of shape.

    On other occasions, I would be sitting and not exerting myself and would start sweating out of nowhere. It also would happen doing seemingly light chores around the house. I remember thinking – am I getting old!

    After a period of time I did mention it to the Doctor who thought maybe it was some kind of thyroid issue, so tested for that which of course turned out not be the case but there was no real follow-up.

    Since my heart attack, I am noticing some sweating which may be part of recovering and a reminder to me not to overdo, but I will follow-up with the Doctor on this as maybe I’m making the wrong assumptions again.

    Keep well, and thanks again for sharing your knowledge and experiences with us. I am learning so much!

    Liked by 1 person

    1. Hello Kathleen – I’m so glad you’re learning a lot, although I’m not happy that it took a serious diagnosis to even be interested in learning more! I often tell my readers and audiences that their only job now is to become the world expert in their diagnosis – and you are on your way now!

      I’m also glad you mentioned that “out of the blue” sweating symptom. Those unusual episodes (ones that are far out of proportion to the amount of effort being used or the air temperature) can often be the kind of symptoms many heart patients overlook – and yet any symptom that does not feel “normal” to you is the one that might be suspicious.

      Good luck at your next doctor’s visit – take care, and stay safe. . . . ♥


      1. Thanks Carolyn. In terms of wanting to learn more, about 2 years ago a Doctor had told me my risk of heart disease over the next 10 years was ‘low’, and to keep doing what I was doing and add more omega 3’s, veggies etc. so I learned more about those aspects but in hindsight, I should have learned more about heart disease in general including symptoms.

        I ‘accepted’ the status of ‘low risk’ at face value. I also had major orthopaedic surgery in 2020 and the pre-op heart tests looked ‘normal’. These things turned out to be a false sense of security, if you know what I mean.

        It’s a hard lesson in taking things for granted and too easily accepting medical opinions. I am grateful to be here to tell the tale. Live and learn!!

        Liked by 1 person

        1. Kathleen, no wonder you accepted your doctor’s “low risk” prediction at face value! Why would you have decided two years ago to learn more about heart disease in general after what your doctor had just told you – or again after your “normal” pre-op test results? Most women, including me, would have happily turned that page and moved on to tackle the ‘real’ problems in life.

          Current risk calculators used by physicians are based on numbers: blood pressure, cholesterol, blood sugars, how many cigarettes smoked per day, etc. – all based on numbers in (white, male) research subjects for the past four decades. Even the lab animals have been male animals. Anything that can’t be measured with numbers (like sweating, for example) is barely on their radar.

          Heart disease must have seemed like a doctor-endorsed non-issue to you. Had you not been already reassured by two different people with the letters M.D. after their names, perhaps you might have been puzzled enough by your experience with unusual sweating to mention those episodes to your doctor. Whether any doctor would have sat up straight and referred you for testing based on a history of weird sweating is another story.

          Meanwhile, you can’t unknow what you now do know. Build on that, stay curious and, as you say – live and learn! ♥


  5. Hi Carolyn,
    I still fall outside of all those things. My ability to experience chest pain has only been in the past two years after had my A-ICD implanted 5 years ago.

    I have had shortness of breath all my life as my restricted bronchial tube has never allowed me to fully inflate my lungs, born with bronchial asthma. I break out in a heavy sweat the moment I fall into a deep sleep. I wake shortly thereafter because I break out in a rash from my own sweat.

    So I would ignore all those things as ‘normal’, or they are normal for me.


    1. Hi Robin – your particular experience is unique, as you have mentioned here in previous comments. You’re one of a kind!

      Even when we’ve learned to describe frequent symptoms as “normal” for us over time, it doesn’t always mean they’re not distressing or uncomfortable.

      Take care, stay safe. . . ♥


  6. Dear Carolyn… thank you for this article…along with what you write above, I want to share a recent discovery I had participating in a healthy ageing nutrition study called the ZOE Health Study here in the UK.

    Part of the participation involves wearing a glucose monitor (the 24 hour a day white button type you put on your upper arm that measures the glucose of the interstitial fluid). We also log in the foods we eat…

    In the first few days/nights especially I noticed awaking with ‘chest pain/discomfort’ and feeling a bit shaky….and checked the glucose monitor and it showed very low glucose. After the first night, I made sure I had a snack (protein, juice, cracker) to eat right away and over the testing period of two weeks, I made sure I ate a healthy snack before bed.

    No more chest discomfort…I have since been to the GP and learned about how our adrenals amp up the liver to release glucose when our blood sugar goes low into hypoglycemia….the connection between BLOOD SUGAR and SWEATING is a connection I made a few weeks ago now.

    Our body is like a symphony and blood sugar/electrolyte levels are all important in keeping us going… I have since had tests from my GP addressing the heart issue after months of tests showing nothing ‘wrong’ with my heart.

    I write to share this so others can perhaps also address the glucose issue as a part of self-care and engaging with our doctors.

    Liked by 1 person

    1. So interesting, Isabella – aren’t you glad you volunteered to participate in that ZOE study?

      Sweating is indeed associated with a number of bodily functions when they go sideways – as you found with your own symptoms. We know that sweating (along with feeling hungry, trembling or shaky) is a typical early warning sign in hypoglycemia (low blood sugar).

      The body is an amazing machine that is constantly adapting and adjusting to every cell!

      Take care, stay safe. . . ♥


    1. Hello Marilyn – yes, “acute coronary syndrome” is a term used to describe a range of conditions associated with sudden, reduced blood flow to the heart muscle – including heart attack and unstable angina.

      Take care, stay safe. . . ♥


  7. Yes, I experienced profuse sweating. It came on suddenly after experiencing nausea. It felt like I was outside in the sun sweating as if you were mowing the lawn, which I don’t. Then cold chills followed. I knew something was wrong. The diagnosis was a 100% blockage in the widow-maker artery.

    Liked by 1 person

    1. Hello Maxine – mowing the lawn on a hot day is such a good analogy: when my first heart attack symptoms struck, I too started sweating as if I were working hard outside on a hot day – except it wasn’t a hot day!

      I’m so glad you followed your gut feeling that something was NOT RIGHT.

      Take care, stay safe. . . ♥


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