Carlos Solis
Women have dealt with hot flashes for centuries—sometimes mildly irritating, sometimes utterly draining. In 1582, Dr. Jean Libo of France was among the first to document the phenomenon. Even though science understands hot flashes and night sweats far better now, one question still stumps experts: “We can’t explain why they don’t happen to everyone,” says Dr. Monica Christmas, an obstetrician-gynecologist at the University of Chicago and director of its menopause program.
What’s actually happening inside a woman’s body during a hot flash?
A hot flash is a sudden burst of heat that often comes with skin flushing and sweating. It usually lasts only a short time—about one to five minutes.
During a hot flash, a woman may feel like her body temperature is high, but physiologically, it usually isn’t. Dr. Christmas says that as women approach menopause and their ovaries make less estrogen, the brain’s internal thermostat—the hypothalamus—becomes hypersensitive even to small temperature changes.
Newer research paints a more complex picture. When the brain senses low estrogen, hypothalamic nerve cells called KNDy neurons become hyperactive and release neurotransmitters—chemical messengers the brain uses to communicate with the body. Those neurotransmitters include kisspeptin, dynorphin, and neurokinin B.
The body “thinks” it is overheating even when core temperature barely changes. In response, blood vessels dilate to help disperse some of the heat, and that dilation triggers reflex sweating.
Studies also show that women who experience stronger and longer hot flashes and night sweats face a higher risk of cardiovascular disease.
That doesn’t mean treating hot flashes will automatically lower heart disease risk, but it does mean these women deserve closer attention to blood pressure, cholesterol levels, and lifestyle factors.
What to do if you have hot flashes
Medical treatments exist for women who suffer from severe hot flashes.
Estrogen-based treatments can help, but not every woman—including those with a history of blood clots or breast cancer—can take them.
Fortunately, new insights into the role of KNDy neurons have led to treatments that block the brain signals that trigger hot flashes. In 2023, the FDA approved a drug called Veozah (fezolinetant). The drug targets the neurokinin 3 receptor, which plays a key role in regulating body temperature.
A drug called elinzanetant reached the market in 2025. It blocks neurokinin 1 and neurokinin 3 receptors, interrupting the process that causes hot flashes at two points instead of one.
Cognitive behavioral therapy and hypnosis have also produced good results in easing hot flashes.
If hot flashes bother you, see your doctor for evaluation and treatment. Also, in some cases hot flashes or night sweats can signal other conditions, including thyroid disease, cancer, or infections.
Adapted from Popular Science
