What causes night sweats in adults?

Sweating, an essential biological function, is crucial in regulating body temperature. However, the body’s cooling mechanism takes on a more disruptive role when it comes to night sweats. Night sweats can severely impact sleep quality, leaving individuals feeling drenched and fatigued. Because night sweats can significantly disrupt sleep quality, this comprehensive guide aims to empower you with the knowledge needed to navigate and mitigate this nocturnal challenge successfully. We’ll thoroughly explore the intricacies of night sweats, examining what they are, their causes, practical relief solutions, and when it might be appropriate to seek professional help.

What are night sweats?

Night sweats involve an abnormal escalation of sweating during sleep, often unrelated to environmental warmth, and lead to soaked clothes and bedding. This nocturnal perspiration disrupts sleep patterns and emphasises the distinctive physiological nature of night sweats compared to sweating experienced during wakefulness. Waking up feeling dehydrated becomes common, necessitating increased water uptake to compensate for lost fluids.

Physiologically, night sweats differ significantly from normal daytime perspiration. During the day, perspiration primarily serves the crucial function of cooling the body down in response to increased temperature or physical exertion.

What causes night sweats?

Understanding the phenomenon of night sweats is pivotal for deciphering its multifaceted causes, each exerting a unique influence on the body. Delving deeper into these causes unveils a complex interplay.

Anxiety and stress

Night sweats are intricately linked to the activation of the brain’s “fight or flight” mechanism in response to anxiety. In the case of anxiety disorders or chronic anxiety, this mechanism reacts disproportionally to specific situations. Individuals with anxiety disorders experience intense fear responses in their brains and bodies, even when the circumstances don’t warrant such reactions. Activating the “fight or flight” system leads to a redirection of blood to energy-demanding areas, inducing vasoconstriction – the narrowing of blood vessels. As a consequence, the body heats up. To prevent overheating, the body initiates sweating, a natural cooling mechanism aimed at restoring equilibrium.


Certain classes of medications have been identified to potentially induce night sweats as a side effect. Antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs), may disrupt the body’s thermoregulation, contributing to excessive sweating during sleep. Antipyretic drugs, designed to reduce fever, can paradoxically increase sweating. Hormone-based medications, such as hormonal contraceptives or hormone replacement therapy (HRT), may cause hormonal imbalances, thus triggering night sweats. Understanding the impact of these medications on the body’s regulatory systems is crucial, as their influence on neurotransmitters, temperature control, or hormonal fluctuations can collectively contribute to nocturnal perspiration.


Hormonal imbalances, particularly disruptions in oestrogen levels, significantly contribute to night sweats. Approximately 75% of post-menopausal women experience vasomotor symptoms. These symptoms include hot flushes, night sweats, palpitations, and migraines. In menopause, the decline in oestrogen levels impacts the hypothalamus, the body’s temperature control centre, leading to dysregulation. This imbalance tricks the body into perceiving a need for cooling, prompting excessive sweating to dissipate heat. Additionally, hormonal disorders beyond menopause, such as thyroid dysfunction or diabetes, can further disturb the delicate interplay of hormones involved in temperature regulation, manifesting in disruptive night sweats. Understanding these hormonal intricacies is pivotal for effective management.

Environmental factors

Environmental factors wield a significant influence on the occurrence of night sweats. Sleeping in a hot room or wearing too many layers can create a thermal imbalance, prompting the body to initiate cooling mechanisms, including sweating during sleep. Maintaining an ambient temperature conducive to rest is crucial, as the body’s natural cooling process becomes disrupted when external conditions interfere. Adequate ventilation and breathable sleep attire can mitigate temperature-induced night sweats, emphasising the pivotal role of environmental considerations in fostering a comfortable and sweat-free sleep environment.

Alcohol consumption

Alcohol consumption can contribute to night sweats through its vasodilatory effects. The ingestion of alcohol leads to increased blood flow and dilation of blood vessels, resulting in elevated body temperature. Excessive perspiration occurs as the body attempts to cool down, particularly during sleep. This phenomenon is exacerbated with heavy drinking, intensifying the vasodilation and subsequent rise in nocturnal sweating. In light of the physiological impact of alcohol on the circulatory system and temperature regulation, it is important to drink in moderation to mitigate this nocturnal discomfort, alongside the myriad of other health issues associated with heavy alcohol consumption.

Underlying medical issues

Underlying medical issues can serve as potent triggers for night sweats, signalling various health concerns. Infections, whether common or severe, can induce night sweats through the body’s immune response. When combating infections, the release of pyrogens induces fever, prompting thermoregulatory mechanisms, including increased sweating to dissipate heat.

Autoimmune disorders, like rheumatoid arthritis and lupus, can contribute to night sweats due to the immune system mistakenly attacking healthy cells, inducing inflammation. This inflammatory response disrupts thermoregulation, leading to heightened night-time perspiration. The chronic nature of autoimmune conditions and continuous immune system activation increases the likelihood of night sweats.

Cancers, including lymphomas and leukaemias, can induce night sweats through inflammatory responses triggered by abnormal cells. Substances like cytokines released during this process may disrupt temperature regulation, causing fluctuations manifesting as night sweats. The heightened metabolic activity associated with combating cancer cells can increase heat production. Often, night sweats may be the initial presenting complaint of a patient with a new diagnosis of cancer; thus, it is important always to see a qualified healthcare professional if you are experiencing such symptoms.

How to stop night sweats and get a better night’s sleep?

Addressing night sweats caused by underlying health issues involves symptom management and treating the root cause. Consultation with healthcare professionals, diagnostic tests, and tailored treatment plans are integral components of managing night sweats in medical conditions.

Investing in good bedding materials

Choosing bedding materials that prioritise moisture-wicking properties significantly enhances the overall sleep environment. Opting for fabrics like bamboo and high-quality microfibre goes beyond mere comfort; it actively regulates body temperature throughout the night. These materials efficiently draw moisture away from the body, preventing discomfort caused by excess perspiration. Additionally, the breathability of these fabrics promotes optimal air circulation, creating a conducive setting for restful sleep by ensuring that body heat is effectively dissipated, thus addressing one of the contributing factors to night sweats.

Practising relaxation techniques

Incorporating relaxation techniques into one’s pre-sleep routine holds profound benefits in managing stress and anxiety levels, which can be instrumental in reducing night sweats triggered by emotional factors. Deep breathing exercises, meditation, and mindfulness practices serve as powerful tools to unwind the mind and alleviate the physiological responses associated with stress. By fostering a state of mental calmness, these techniques not only contribute to a more serene sleep onset but also act as a preventative measure against the activation of the body’s stress response during the night, consequently minimising the likelihood of disruptive night sweats.

Using sleep trackers

Using sleep trackers and wearable devices represents a proactive approach to gaining valuable insights into individual sleep patterns. These technological tools go beyond mere data collection; they comprehensively analyse sleep cycles, duration, and interruptions. Individuals can make informed lifestyle adjustments by identifying patterns and potential triggers for night sweats. Moreover, sharing this data with healthcare providers facilitates a more nuanced assessment, enabling personalised recommendations. Sleep trackers empower individuals to participate in their sleep management actively, fostering a collaborative approach between individuals and healthcare professionals to address the various aspects of nocturnal perspiration.

Is there a link between genetics and night sweats?

The role of genetics in the occurrence of night sweats adds a layer of complexity to understanding the phenomenon of night sweats. Research has unveiled that certain individuals may be genetically predisposed to experiencing nocturnal sweating due to variations in specific genes related to thermoregulation. These genetic factors can influence an individual’s susceptibility to night sweats, shaping how their body responds to various triggers. Moreover, family history emerges as a crucial aspect, indicating a higher likelihood of experiencing night sweats if close relatives have a history of similar issues.

This genetic predisposition is not confined to a single gene but encompasses a network of genes orchestrating the intricate dance of temperature regulation. Exploring this genetic dimension sheds light on why some individuals exhibit heightened vulnerability to night sweats, presenting a compelling avenue for personalised healthcare. Genetic considerations demand a nuanced approach to night sweat management. As the field of genomics advances, unravelling the intricate workings of genes involved in thermoregulation, holds promise for tailoring interventions based on an individual’s genetic makeup.

Is there a link between night sweats and sleep apnoea?

Recent research has uncovered a fascinating link between sleep apnoea and changes in sweat metabolism. A collaborative effort between the University of Córdoba and the Maimonides Institute for Biomedical Research in Córdoba found that analysing sweat metabolome alterations, mainly at night, could indicate the severity of sleep apnoea. “By analysing the sweat metabolome and its alterations, we were able to see what stage of the disease these patients were in,” explains Laura Castillo, the study’s lead author.

 “The advantages of using sweat over other samples are clear: it is a non-invasive and clean sample since, unlike the case with blood, we don’t have to remove proteins, and it’s much easier to analyse and detect metabolites.” This ground-breaking study highlights the potential of sweat samples in tracking the development of sleep apnoea and monitoring its effects, such as cardiovascular problems. Sweat analysis could serve as a non-invasive index to diagnose and manage the severity of sleep apnoea in the future.

When should you be concerned about night sweats?

The multifaceted nature of night sweats necessitates a nuanced approach, considering factors such as individual variations, lifestyle choices and medical interventions. Despite the plethora of strategies presented, the persistence of night sweats warrants personalised attention. If you still find yourself grappling with persistent night sweats after earnestly attempting the suggested solutions, you may wish to consider consulting with a sleep specialist.



The articles in the Sleep Psychiatrist blog have been written by Dr Dipesh Mistry. They are for educational and informational purposes only, and should not be regarded as medical advice. Always seek advice from your sleep physician, personal physician, psychiatrist, or any other suitably qualified healthcare professional in relation to any interventions or treatment for your sleep, mental health or physical health.

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