Can immunotherapy cause night sweats, and how to cope

Night sweats can occur during cancer treatment and may happen alongside hot flashes. These sweating episodes are reported across several cancer therapies, and some people continue to have them after treatment ends. ^[1] Night sweats are often linked to hot flashes but can also occur on their own. ^[1]

Can immunotherapy cause night sweats?

Immunotherapy can trigger flu‑like symptoms such as chills and fatigue, and these can be associated with sweating episodes. These side effects stem from the immune system reacting to the treatment, and while sweating is not always listed separately, chills and flu‑like symptoms commonly involve temperature dysregulation that can include night sweats. ^[2] Most immunotherapy side effects can be managed safely if recognized and treated early. ^[3]

Other cancer treatments like chemotherapy, radiation, hormone therapy, and certain surgeries are well known to cause hot flashes and night sweats. This shows that sweating symptoms are a recognized phenomenon across cancer care, not limited to one treatment type. ^[4] Lymphoma itself is a cancer commonly associated with night sweats, which means symptoms can come from the disease as well as the therapy. ^[4]

Why they happen

Two main pathways can lead to night sweats during immunotherapy: flu‑like immune activation and endocrine (hormone) changes. Flu‑like reactions (chills, feverish feelings) reflect immune stimulation and frequently bring sweating. ^[2] Endocrine side effects, such as thyroid dysfunction or pituitary inflammation, can alter metabolism and temperature control, potentially causing sweating or heat intolerance. ^[5] Thyroid problems are a recognized cause of excessive sweating more broadly. ^[6]

Thyroid dysfunction is a known immune‑related adverse event, and routine monitoring during checkpoint inhibitor therapy is recommended. Suggested monitoring includes TSH and free T4 periodically, with cortisol as indicated by symptoms, because late endocrine dysfunction can occur. ^[7] Published clinical experience shows thyroid abnormalities and hypophysitis are among the most common endocrine toxicities from checkpoint inhibitors. ^[5]

When to seek medical care

Contact your care team promptly if night sweats are new, severe, or accompanied by fever, weight loss, palpitations, heat intolerance, or persistent fatigue. These features can point to infection, disease activity (such as lymphoma), or endocrine issues that need testing. ^[4] Many immunotherapy side effects are safer and easier to manage when treated early. ^[3]

Practical coping strategies

Simple home measures can reduce discomfort from night sweats. Try keeping the room cool with open windows or fans, wearing loose cotton sleepwear, and practicing slow, deep breathing to ease symptoms. ^[8] Some people explore acupuncture, though benefits are mixed; discuss this option with your clinician first. ^[8]

Daytime habits may help your overall energy and sleep quality if sweating disrupts rest. Short daytime naps (15–20 minutes) and light physical activity like walking can lessen treatment‑related fatigue and improve nighttime sleep. ^[9] Managing skin irritation from sweat with breathable clothing and gentle skincare can also help comfort. ^[10]

Medical steps your team may consider

Evaluation for endocrine causes often includes thyroid tests (TSH, free T4) and, if indicated, cortisol, especially during checkpoint inhibitor therapy. Regular testing is commonly advised during treatment and at intervals afterward, because dysfunction can appear late. ^[7] If thyroiditis or Graves’ disease is suspected, thyroid antibodies may be checked to guide diagnosis and management. ^[7]

If night sweats relate to hot flashes from cancer therapy, tailored treatments may be discussed. Approaches range from lifestyle strategies to medications selected by your clinician based on your cancer type and overall health. ^[1] Because hot flashes and night sweats are common across cancer treatments, individualized management is typical and can improve quality of life. ^[11]

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Summary table: causes and actions

Possible cause	What it is	Clues you might notice	What to do
Flu‑like immune response	Immune activation from immunotherapy	Chills, feverish feelings, sweats	Report symptoms; supportive care, monitor severity [2] [3]
Endocrine side effect (thyroid/pituitary)	Immune‑related hormone dysfunction	Heat intolerance, palpitations, fatigue, weight changes	Ask about TSH, free T4, cortisol testing; treat per results [7] [5]
Other cancer therapies	Chemo, radiation, hormone therapy, surgery	Hot flashes and night sweats during/after treatment	Use cooling, clothing, breathing strategies; discuss options [4] [1]
Disease activity (e.g., lymphoma)	Cancer itself causing sweats	Night sweats with fever or weight loss	Inform your team for evaluation and imaging/labs as needed [4]

Night sweats are a recognized symptom in cancer care, and with early communication and practical strategies, they can often be managed effectively. ^[1] Most immunotherapy side effects are manageable when identified early and addressed with your care team. ^[3]