Hot Flashes: How They Work, Common Triggers and Treatments

What does a hot flash feel like?

A hot flash is a sudden wave of heat, usually felt most in the chest, neck and face. It often comes with flushed skin, sweating, a faster heartbeat and sometimes a surge of anxiety, then chills as your body cools down. A 2019 review describes typical episodes as lasting one to five minutes. Hot flashes that happen during sleep are called night sweats, and they can be intense enough to soak pajamas and bedding.

Doctors group hot flashes and night sweats together as vasomotor symptoms. They are among the most common symptoms of perimenopause and menopause, and they range from mild warmth a few times a week to many drenching episodes a day.

How do hot flashes work?

Your hypothalamus, a small region at the base of the brain, acts as a thermostat. Normally it tolerates small changes in core body temperature without reacting. This range is often called the thermoneutral zone.

As estrogen falls and fluctuates, that zone narrows. A slight rise in core temperature, one your body would once have ignored, is now treated as overheating. The brain responds by widening blood vessels in the skin to release heat (the flush), switching on sweat glands, and raising heart rate. Once heat is lost, you may feel chilled.

Researchers have identified a group of hypothalamic nerve cells, sometimes called KNDy neurons, that help drive this response. They use a signaling molecule called neurokinin B, and without estrogen’s restraining effect they become overactive. The review above also points to roles for serotonin and norepinephrine, which is why some antidepressants reduce hot flashes. Newer medicines such as fezolinetant work by blocking neurokinin B’s receptor.

How long do hot flashes last?

Individual episodes are short, but the symptom often isn’t. In the SWAN study of more than 3,000 U.S. women, frequent hot flashes lasted a median of 7.4 years in total and continued a median of 4.5 years after the final period. Women whose hot flashes started early in the transition, and Black women, tended to have them longest. Our guide to how long hot flashes last covers what affects the timeline.

By the numbers

Short episodes, long timeline

1–5 mintypical length of a single hot flashSource: 2019 review

7.4 yrsmedian total duration of frequent hot flashes in SWANSource: Avis 2015

4.5 yrsmedian time they continued after the final periodSource: Avis 2015

What triggers hot flashes?

The underlying cause is hormonal, but certain things can set off individual episodes. Common triggers include:

• Warm rooms, hot weather, heavy bedding or hot showers.
• Alcohol.
• Caffeine. In a Mayo Clinic survey of about 1,800 women, caffeine users reported more bothersome hot flashes than non-users, although the study couldn’t show cause and effect.
• Spicy food and hot drinks.
• Stress and anxiety.
• Smoking.

Triggers differ from person to person, so a few weeks of noting when hot flashes happen can help you spot yours. Be realistic, though: The Menopause Society’s 2023 nonhormone position statement found avoiding triggers and cooling techniques have not been shown in trials to reduce how often hot flashes occur. They may make episodes more bearable rather than less frequent.

Which treatments work for hot flashes?

Hormone therapy

The Menopause Society calls hormone therapy the most effective treatment for hot flashes and night sweats. Estrogen comes as patches, gels, sprays, pills and other forms. Women who have a uterus also need a progestogen to protect the uterine lining. Hormone therapy is generally not recommended for people with a history of breast or endometrial cancer, blood clots, stroke, heart attack, liver disease or unexplained vaginal bleeding, and risks rise for women who start more than 10 years after menopause or after age 60.

Amie HRT+ is one option: a compounded cream that combines estradiol and progesterone, with the strength chosen by a licensed clinician after an online review, for hot flashes, night sweats, sleep and other menopause symptoms. It is not FDA-approved. FDA-approved estradiol and progesterone products are also widely available. A clinician decides which, if any, is appropriate for you.

Non-hormone prescriptions

For women who can’t or prefer not to use hormones, The Menopause Society’s nonhormone statement recommends:

• Fezolinetant, which blocks the neurokinin B receptor. In the SKYLIGHT 1 trial, it reduced the frequency and severity of moderate to severe hot flashes compared with placebo, with effects seen from the first week and maintained for a year. Liver blood tests are required before and during treatment because of a risk of rare liver injury.
• Certain antidepressants (SSRIs and SNRIs), including low-dose paroxetine. Some SSRIs interfere with tamoxifen, so women with breast cancer need careful choice.
• Gabapentin, which can be helpful for night sweats when taken at bedtime.
• Oxybutynin, a bladder medicine with some evidence for hot flashes, though it is generally avoided long-term in older adults because of effects on thinking.

CBT and clinical hypnosis

Both are recommended in the nonhormone statement. They don’t necessarily reduce the number of hot flashes, but they reduce how much they bother you and interfere with life, and they have no drug side effects. CBT for insomnia is also the first-line treatment for the poor sleep that often comes with night sweats. See menopause insomnia.

What about natural remedies?

Practical ways to get through a hot flash

These may not change how often hot flashes happen, but many women find them helpful for comfort, as the National Institute on Aging suggests:

• Dress in layers you can remove quickly, in breathable fabrics.
• Keep a fan at your desk and bedside, and the bedroom cool.
• Keep a cold drink nearby and sip at the start of a flash.
• Use moisture-wicking pajamas and bedding, and keep a spare set by the bed.
• Note your personal triggers and cut back on the ones you can.

When should you see a doctor about hot flashes?

Hot flashes are common, but they are worth discussing with a clinician if they disrupt your sleep, work or quality of life. Seek prompt evaluation if:

• Hot flashes start before age 40, which can signal early loss of ovarian function.
• Night sweats come with fever, unexplained weight loss or swollen lymph nodes.
• Flushing comes with palpitations, tremor and weight loss, or with diarrhea or wheezing.
• Hot flashes return or worsen years after menopause, or began after starting a new medicine.
• You have any vaginal bleeding after menopause.

To compare treatment options in more depth, see our guide to hormone replacement therapy.