What causes hot flashes?

A hot flash is a sudden wave of heat through the face, neck, and chest, often with flushing, sweating, and a racing heart, sometimes followed by a chill. They happen because falling estrogen makes the brain's temperature-control center oversensitive, so it misreads small temperature changes and triggers cooling — sweating and flushing — when it isn't really needed. Hot flashes are the most common menopause symptom, affecting up to about 80% of women. At night, the same mechanism causes night sweats.

How long do hot flashes last?

An individual hot flash usually lasts 1 to 5 minutes. As a symptom, hot flashes (vasomotor symptoms) persist a median of about 7 years, and for some women 10 or more — typically worst around the final period and easing over time. For the full timeline, see how long menopause lasts.

Common triggers

Many women find specific things set off a flash: alcohol, caffeine, spicy food, hot drinks, stress, warm rooms, and tight or synthetic clothing. Keeping a brief diary can reveal your personal pattern so you can sidestep the biggest culprits.

What helps

  • Lifestyle — dress in light layers, keep cool, sip cold water, manage stress, avoid your triggers, and don't smoke (smoking worsens hot flashes).
  • Hormone therapy (HRT) is the most effective treatment and is appropriate for many women — discuss the benefits and risks with a clinician.
  • Non-hormonal prescription options include certain antidepressants (SSRIs and SNRIs) and the newer drug fezolinetant, which targets the brain pathway behind flashes.
  • Mind-body approaches — cognitive behavioral therapy and paced breathing help some women cope.
  • For supplements, see the honest evidence on menopause supplements — most are weakly supported.

When to see a clinician

See a clinician if hot flashes disrupt your sleep, work, or quality of life, to weigh up treatment — effective options exist and you don't have to just endure them. Also mention any unusual features, such as flashes with a pounding heartbeat or that began alongside other new symptoms, which occasionally point to another cause. See how to get menopause care.