Excessive sweating (night sweats, hot flashes) can be a sign of cancer or may be caused by cancer treatment.
In this article, I provide an overview of excessive sweating, also known as hyperhidrosis, and its association, or lack thereof, with cancer.
I will address the most frequently asked questions on this topic:
- Can excessive sweating be a symptom of cancer?
- Which cancers can cause excessive sweating?
- What is excessive sweating like when you have cancer?
- What solutions are available for excessive sweating when you have cancer?
I have sought to gather information on this topic as objectively as possible by exploring studies published in international medical literature.
You will find all the references to the academic publications I rely on at the end of the article.
💬 The comment section is there for you! Feel free to share your experiences, as they can be valuable to others. Have a good reading!
♻️ Last update: september 2023
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Can Excessive Sweating Be a Symptom of Cancer?
Yes, excessive sweating can be one of the symptoms of cancer, but it is more the exception than the rule.
This is because approximately 5% of the world’s population is affected by excessive sweating (without cancer), a condition known as hyperhidrosis. Hyperhidrosis can be of two types.
Primary Hyperhidrosis (Not Caused by Cancer)
In 90% of cases, people have primary hyperhidrosis (excessive sweating). In this case, excessive sweating is NOT a symptom of cancer.
It is partly of genetic origin and often appears during childhood, adolescence, or early adulthood.
Secondary Hyperhidrosis (Sometimes Caused by Cancer)
In 10% of cases, hyperhidrosis is secondary, meaning there is something else that explains this excessive sweating. For example:
- Excessive alcohol consumption.
- Significant weight gain leading to overweight or obesity.
- Certain diseases, such as hormonal disorders, diabetes, heart failure, Parkinson’s disease, and sometimes cancer.
- The use of certain medications, such as antidepressants, and sometimes medications or other cancer treatments.
A study followed 420 people who sought medical attention at a French hospital (in Tours) for a recent and generalized problem of excessive sweating. The authors concluded that if sweating has been excessive for more than a year, the risk that it is due to malignant cancer or infection is very low.
Here are the most frequently found causes of sweating in these individuals:
- 17%: No cause found.
- 14%: Organ cancer (most often lung cancer).
- 14%: Malignant hematologic disorders (most often non-Hodgkin’s lymphomas).
- 10%: Infectious diseases (most often tuberculosis).
- 17%: Other inflammatory conditions.
- 28%: Other non-inflammatory conditions. (Collercandy 2022)
How to Determine if You Have Primary or Secondary Hyperhidrosis?
If you have had excessive sweating for a long time, especially if it appeared between childhood and early adulthood, there is very little risk that it is a symptom of cancer. Of course, there is nothing wrong with discussing it with your general practitioner if it concerns you.
In any case, the symptom of sweating alone is not enough to diagnose cancer. The most indicative and common symptoms are rather unexplained fever, a general deterioration in health, and unexplained weight loss, often accompanied by a C-reactive protein (CRP) level of >5.6 mg/L (after a blood test).
Which Cancers Can Cause Excessive Sweating?
All cancers, when treated, have the potential to cause excessive sweating, and this can persist in some individuals even after the completion of treatment.
Internet users are particularly concerned about the link between sweating and:
- Lung cancer,
- Liver cancer,
- Pancreatic cancer.
- Lymphomia (night sweats)
- Ovarian cancer
- Prostate cancer
These are indeed cancers that can trigger excessive sweating, but cancers located elsewhere can also have this effect.
What Is Sweating Like When You Have Cancer?
In the case of cancer, excessive sweating can manifest in two main ways:
- Hot flashes.
- Night sweats.
When You Have Cancer Excessive sweating can occur mainly at night. During sleep, we tend to sweat more, to the point that we sometimes wake up soaked, with the sheets drenched. These are known as night sweats.
Suddenly during the day, you may feel a sudden, intense heat in the face, neck, and chest. Often, your face may become red. Then you start sweating profusely. These are referred to as hot flashes.
Male hot flashes: symptoms of cancer ?
No, male hot flashes are not sufficients symptoms of cancer. Not any more than in women. It’s not a sufficient sign to make a cancer diagnosis.
The Smell of Sweat in Cancer Cases
When someone has cancer that is being treated, their sweat can change in odor. This is partly because the body excretes some of the substances found in cancer treatments through sweat.
Why Do Cancer or Cancer Treatments Cause Increased Sweating?
Excessive sweating in the case of cancer can have different causes in women and men.
Cancer & excessive sweating in Women
Some cancers lead to premature menopause. This occurs when the ovaries no longer produce a hormone called estrogen. This can happen when both ovaries are removed during surgery, either through:
- bilateral ovariectomy
- or hysterectomy.
However, excessive sweating can also result from any cancer treated with:
- chemotherapy, chemo treatment,
- hormone therapy (such as tamoxifen and aromatase inhibitors),
- radiation therapy,
- or medications (opioids for pain, tricyclic antidepressants, and steroids).
In patients with breast cancer, severe hot flashes mainly occur in those who experience sleep problems, significant pain, or mental distress.
A study followed 104 women after their breast cancer treatment, which included tamoxifen. Over 70% of these women experienced symptoms of premature menopause that persisted for up to 2 years. The most common symptom was hot flashes and excessive sweating.
Cancer & excessive sweating in Men
In men, the testicles produce testosterone. Surgical removal of one or both testicles for prostate cancer treatment can trigger various symptoms, including hot flashes and night sweats.
Hormone therapy with gonadotropin-releasing hormone or estrogens can also cause these symptoms in men.
Other medications, like opioids, tricyclic antidepressants, and steroids, can also induce hot flashes and night sweats.
Sweating Due to Cancer, Not Its Treatment
Some people experience excessive sweating unrelated to their cancer treatment, and they do not have primary hyperhidrosis. This can happen with certain cancers, including:
- carcinoid tumors,
- bone cancer,
- liver cancer,
- and mesothelioma.
The exact reasons why certain types of cancer cause night sweats are not fully understood. It could be related to the body’s efforts to fight the cancer or changes in hormone levels. When cancer induces fever, the body may sweat excessively in an attempt to cool down.
How to know if sweating is due to cancer or something else?
Keep in mind that if you don’t have cancer, it is highly unlikely that your sweating issues are related to cancer.
If you have cancer, reflecting on when the various problems you are experiencing appeared is one way to make a connection. Did you sweat excessively BEFORE being diagnosed with cancer? If so, was it only a few months or several years before, or have you been sweating excessively only since you started treatment?
Based on your answers to these questions, you should already have a clearer idea of the relationship between your cancer and the sweating problems you are facing.
If you have cancer, you are likely under the care of an oncologist. This is the person you should discuss your sweating problems with. If you don’t have cancer, your primary care physician would be your point of contact.
These healthcare professionals will ask you questions and may conduct additional tests to identify the cause of your hyperhidrosis (excessive sweating).
What are the solutions for excessive sweating when you have cancer?
There are many possible treatment options for excessive sweating, each with its own advantages and disadvantages. The choice of treatment will depend on:
- The location of your hyperhidrosis.
- The causes of excessive sweating (cancer? Genetic hyperhidrosis? Cancer treatment?).
- Your personal preferences.
- Other treatments or conditions you may have.
All treatments for hyperhidrosis can have side effects.
Sweating Solutions and Tips
Before considering treatments, various measures can be implemented to try to limit sweating or its negative impact:
- Install a fan or naturally ventilate the room in which you sleep or live to circulate the air.
- Wear loose-fitting clothing, preferably in cotton.
- Sleep in sheets that limit sweating.
Treatments for Primary Hyperhidrosis
If you have primary hyperhidrosis, you will find many informative articles on different treatments for hyperhidrosis on the Hyperhidrosis’Observatory website. Here are a few (soon in Ensligh):
- Antiperspirants containing aluminum or other substances.
- Medications for sweating like Oxybutynin.
Some, like antiperspirants or iontophoresis, can be used without necessarily consulting a doctor. (See also my article: What kind of doctor specializes in sweating?)
Treatments for Hyperhidrosis in the Case of Cancer
If you have cancer, consulting a doctor to find an appropriate treatment is essential. There are many possible drug interactions, and it’s better to have the opinion of a doctor who is familiar with all the treatments you are undergoing.
Here are some treatments sometimes given for night sweats and hot flashes in the case of cancer:
- Hormone replacement therapy (hormonal medications) in women who have early or “natural” menopause. However, this treatment is contraindicated in some women, including those with breast cancer.
- Estrogens, a progestin, antidepressants, and anticonvulsants in men who have had prostate cancer.
- Non-estrogen medications: megestrol and medroxyprogesterone (medications like progesterone), some antidepressants, anticonvulsants, and clonidine.
All of these treatments come with various types of side effects. Therefore, it’s essential to discuss the potential benefit-to-risk ratio in your case with your healthcare providers.
For some people, non-drug treatments that help manage stress can have an impact on hot flashes and help reduce them (see my opinion on hypnosis and sweating).
Do you have any comments or questions? Your comments are welcome 🙂 !
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Collercandy N, Thorey C, Diot E, Grammatico-Guillon L, Thillard EM, Bernard L, Maillot F, Lemaignen A. When to investigate for secondary hyperhidrosis: data from a retrospective cohort of all causes of recurrent sweating. Ann Med. 2022 Dec;54(1):2089-2101. doi: 10.1080/07853890.2022.2102675. PMID: 35903938; PMCID: PMC9455328.
Sung S, Min YH, Park SK, Lee SB. Hot flushes and sweating, sleep problems, joint and muscular discomfort, and physical and mental exhaustion in breast cancer survivors during the first 24 months of tamoxifen therapy: a prospective observational study. Front Oncol. 2022 Aug 2;12:844926. doi: 10.3389/fonc.2022.844926. PMID: 35982968; PMCID: PMC9380584.
Cancer.org. Managing cancer-related side effects. Skin problem. What are hot flashes and sweating
Cancer.gov. Side effects – Hot flashes.
Kaplan M, Mahon SM, Lubejko BG, Ginex, PK. Hot Flashes: Clinical summary of the ONS Guidelines™ for cancer treatment–related hot flashes in women with breast cancer and men with prostate cancer. Clin J Oncol Nurs. 2020; 24(4): 430-433.
National Cancer Institute (NIH). Hot flashes and night sweats (PDQ®)–patient version. 2019.
Written by Nelly Darbois
I founded this website in 2012. Since then, I’ve been providing information and positive support to people suffering from excessive sweating. I’m also a physical therapist and science writer, living in French Alps 🌞❄️.