Hot flashes and night sweats are a type of vasomotor symptom, which occur when the blood vessels constrict or dilate. In Canada and the UK, they may also be referred to as hot flushes.
Hot flashes and night sweats are the most reported perimenopausal symptoms, experienced by 70-85% of women at some point during the menopausal transition. Hot flashes and night sweats feel like a strong wave of heat traveling through the upper body and face. This is followed by sweating and sometimes chills.
Hot flashes may be felt as:
Flashes can be very short or last up to a few minutes, and occur at any time of day. However, they most frequently occur at night, commonly between 6-8 AM and 6-10 PM.
Hot flashes begin during perimenopause but may persist post-menopause. Approximately 25% of women continue to experience hot flashes up to 5 years or more after menopause.
Hot flashes and night sweats are often most intense at the start of perimenopause. They can vary from very mild to severe, which can lead to sleep deprivation. They may be accompanied by pain, sudden anxiety or depression.
Current research indicates that Black women may have more intense hot flashes than others, as do heavier women.
There are a number of techniques you can try to minimize the frequency or alleviate the severity of hot flashes.
Hot flashes are linked to insomnia and increased risk of cardiovascular disease, so being proactive about managing them has added benefits into the future. Triggers and successful interventions for hot flashes can vary woman-to-woman, so journaling or tracking hot flashes alongside common stressors may improve your experience.
If you do not already have a healthcare practitioner who is familiar with identifying and treating symptoms of menopause, the North American Menopause Society provides a list of menopause practitioners here.
Prescriptions for safe and FDA-approved Hormone therapy (HT) with estrogen are available and often effective for reducing hot flashes and night sweats. Oral contraceptives (estrogen and progestin) have shown effectiveness in randomized studies. However, these come with possible side effects such as nausea, migraines and breakthrough uterine bleeding. All options should be carefully discussed with a medical care provider. Many women have success managing their hot flashes with the simpler methods listed in the self-care section.
Breast cancer patients may require non-HT therapies to relieve strong hot flashes. Options include blood pressure-lowering medications or low-dose antidepressants.
New hot flash therapies are currently under development. These include a medication named MNGX-100, which blocks the action of a type of inflammatory cytokine (called G-CSF) from disturbing the hypothalamic “thermostat”.
Perimenopausal estrogen depletion triggers a rise in a neurochemical message called Neurokinin-B (NKB) which triggers hot flash responses in the brain’s hypothalamic “thermostat.” A drug currently in development, SJX-653, blocks NKB action at its receptor (NK3). SJX-653 is being tested as a non-hormonal therapy for moderate to severe vasomotor symptoms. Bijuvia is an FDA-approved drug made of “Bioidentical Hormones” that are copies of natural estrogen (19-β estradiol) and progesterone. This may prove to be helpful for managing hot flashes and night sweats.
Many naturopathic therapies advertise their success with treating hot flashes. In 2015, the North American Menopause Society (NAMS) released a position statement on non-hormonal management of the most common perimenopause symptoms called Vasomotor Symptoms (VMS).  This position statement is aimed at clinicians, to keep them informed about what the scientific evidence shows with respect to the many non-hormonal (naturopathic) management options. The goal is to provide evidence-based guidance that can prevent the use of inappropriate or ineffective therapies and to support the use of effective ones.
* Cognitive behavioral therapy (CBT), a common form of talk therapy, and clinical hypnosis have been shown to be effective in reducing vasomotor symptoms (VMS).
* Paroxetine salt is the only non-hormonal medication approved by the US Food and Drug Administration for the management of VMS, although other selective serotonin reuptake/norepinephrine reuptake inhibitors (SSRIs), gabapentinoids, and clonidine show evidence of efficacy.Learn More
* Weight loss
* Mindfulness-based stress reduction
* S-equol derivatives of soy isoflavones, and stellate ganglion block (additional studies of these therapies are warranted)
There are negative, insufficient, or inconclusive data suggesting the following should not be recommended as proven (ie scientifically supported and guaranteed) therapies for managing VMS, although many may help individual women:
* cooling techniques
* avoidance of triggers such as alcohol and spicy food
* paced respiration
* over-the-counter supplements and herbal therapies
* acupuncture, calibration of neural oscillations
* chiropractic interventions
Although medical professionals are still uncertain as to how hot flashes originate in the body, current research points to disturbances in the temperature-regulating (hypothalamus) and heat-sensing (insula and anterior cingulate cortex) areas of the brain.
Rapid drops in estrogen may cause the hypothalamus thermostat to overreact to small increases in heat, due to neurochemical messages. As a result of this overreaction, the hypothalamus triggers a series of actions in an attempt to rapidly (if erroneously) cool the body. Increased blood flow is directed to the face, neck and torso where dilated blood vessels close to the skin’s surface can help cool the blood supply. This occurs alongside increased sweating to further cool the skin and the underlying blood vessels.
During hot flashes, MRI brain studies of perimenopausal women show that temperature sensors are activated in the brain and signal a sense of strong heat.
Other evidence points to inflammatory cytokine chemical messengers, released from immune system cells, interfering with the thermostat and sensory parts of brains in perimenopausal women.
Hot flashes and night sweats can have a profound impact on quality of life during menopause.
Perimenopausal women affected by hot flashes
Women still experiencing vasomotor symptoms 12+ years after menopause
Reduction in weekly hot flash frequency with oral estrogen hormone therapy
Black women are more than twice as likely to experience hot flashes as White women
However, they can trigger persistent insomnia which should be treated since chronic insomnia is dangerous.
Heavy smokers and drinkers, and women with nutrient deficiencies may experience hot flashes.
Medical research isn’t clear on how hot flashes are triggered, but unstable and decreasing estrogen levels, plus the chemical messages of inflammation, may upset the body’s “thermostat” in the brain.