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What are hot flashes?

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

A hot flash, also called hot flush by some people, is one symptom of menopause that causes your core temperature to rise very quickly. In an effort to cool you down, the body dilates blood vessels in the skin and you begin to sweat. Then you get cold when the air hits your wet skin and your core body temperature is reduced. Some women get 10 or more hot flashes a day with some lasting up to five minutes.

Boston Women's Health Book Collective
Administration Specialist

A hot flash is a sudden sensation of heat, usually in the upper body, that may rise up from the abdomen—or in some cases emanate from the toes—into the chest, back, and head, and may be accompanied by perspiration. Other sensations may include heart palpitations and anxiety. A hot flash may last from about one to five minutes. Once the flash is over, some women may also feel chilled. Women with physical disabilities, such as spinal cord injuries may experience hot flashes in different parts of the body or only on one side.

The reasons women have hot flashes have not been fully explained. In the past, doctors postulated that the onset of hot flashes had everything to do with the decrease in estrogen as a woman approached menopause. However, not all women get hot flashes. What's more, researchers have found that the levels of estrogen do not differ substantially between women who have hot flashes and those who do not.

Other factors that may be involved in hot flashes include the body's core temperature regulation and brain chemicals. The body's thermostat has an upper set point, at which the body's blood vessels open up and perspiration occurs, in an effort to release heat. There is also a lower threshold, at which shivering begins to generate heat. Between these two extremes is a temperature zone at which the body normally functions. Doctors now theorize that the zone between the high and low set points in peri- and post-menopausal women who experience hot flashes is narrower than in women who do not experience any hot flashes.

Our Bodies, Ourselves: Menopause

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Our Bodies, Ourselves: Menopause

FROM THE EDITORS OF THE CLASSIC "BIBLE OF WOMEN'S HEALTH," A TRUSTWORTHY, UP-TO-DATE GUIDE TO HELP EVERY WOMAN NAVIGATE THE MENOPAUSE TRANSITION For decades, millions of women have relied on Our...
Dr. Julia Schlam Edelman
OBGYN (Obstetrician & Gynecologist)

A hot flash is sudden, temporary warmth, with flushing and perspiring. In other words, you become hot, red-faced and sweaty. Some women refer to hot flashes as "power surges."

Certain physical changes occur during a hot flash. First, the body's core temperature goes down, producing central cooling. Then heat is lost through the skin. Skin temperature measurements show that the skin gets several degrees warmer as a hot flash takes place. Perspiring and evaporation cause additional rapid heat loss. A chill may follow the hot flash.

A hot flash is a sensation of heat associated with a red, flushed face, and sweating. This happens when the blood vessels near the surface of the skin dilate in order to cool. Sweating is another way to cool the body. The exact cause of hot flashes is unknown, but may be caused by circulation changes. Sometimes these happen at night and can interfere with sleep. Hot flashes affect every woman differently, but usually lessen in severity with time; however, some women report having them throughout their lives after menopause.

A hot flash is one of the most common symptoms of menopause. You’ll feel your body heat up, and you’ll get a red, flushed face and sweat a lot. This can last a few minutes or longer. Women in menopause or perimenopause can get several hot flashes a day, or several a month. Hot flashes also happen at night (they're called night sweats).

Hot flashes are triggered by fluctuating (changing) hormones during menopause. During this stage of life, a woman’s body makes less of the sex hormone estrogen, which affects the hypothalamus (this gland regulates your body temperature).

During menopause, while your estrogen level decreases, the hypothalamus gets confused and thinks your body is too hot. That signals your body to circulate more blood and your sweat glands to produce more sweat, to get rid of the heat.

Try to figure out what brings on your hot flashes, whether it’s certain drinks (coffee or tea, for example), the weather (maybe it’s hot outside), stress, or certain foods (such as spicy ones). If you can identify the trigger and avoid it, that might help.

Patricia Geraghty, NP
Women's Health

In a hot flash the temperature regulation in the brain becomes too narrow, signaling that the body is too hot when there may be only a slight and typically tolerable difference in temperature. In an effort to cool, the peripheral vessels then dilate and increase in blood supply (the flushing and the heat) and to further the cooling sweat glands go into action (the sweating). During the menopause transition up to 85 percent of women experience hot flashes during the day and night. A single episode may last from a few minutes up to 20 minutes. The newest data says that among women who experience hot flashes, the flashes continue on average for 7 years.

Hot flashes are the most common symptom of menopause; 60-85 percent of menopausal women experience them. Hot flashes can disturb sleep and often result in frequent awakening. Hot flashes usually begin with a flushed sensation and a sudden feeling of heat from the waist that moves up to the chest, neck and face. Accompanying symptoms include perspiration, palpitations, vertigo, nausea, dizziness, headaches, anxiety, weakness and night sweats. Hot flashes last an average of 4 minutes, although they may last as long as 20 minutes. Hot flashes can be infrequent or as often as 15 times per day.

Hot flashes typically begin as a sudden sensation of heat on the face and upper chest that becomes generalized. It can be pretty intense, lasting between 2 and 4 minutes and followed by profuse sweating. Many women also have chills and shivering.

Physiologically, a hot flash happens for the same reason that you sweat in a sauna... the body is trying to cool down. The difference is, you don't really need to cool down, but your menopausal brain thinks you do.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.