What causes hot flashes?

Dr. Jeanne Morrison, PhD
Family Practitioner

It’s estimated that 66 percent to 85 percent of women get hot flashes in midlife, during menopause. At least half of those women stop getting them within a year or two after their period ends. Another 20 percent to 50 percent of women continue getting hot flashes for years after, though they tend to become less intense as time goes by.

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 such as coffee or tea, the weather (maybe it’s hot outside), stress, or spicy foods. If you can identify the trigger and avoid it, that might help.

Although some believe that hot flashes are caused by illness, fevers, or even burning desire - the real causes for hot flashes are the sex hormones in women and men.

Testosterone levels in men and estrogen levels in women can fluctuate. If these hormones are suppressed, this can cause blood vessels to dilate. When the blood vessels dilate, more blood is able to rush through the body. The sudden increase in blood flow is accompanied by more heat, typically to the upper part of the body. An estimated 85 percent of all women will experience hot flashes at some point.

If you are experiencing hot flashes, you may want to discuss it with your doctor, especially if you are too young for menopause. There are other causes for hot flashes, including hyperthyroidism and some types of cancer.

Hot flashes are common occurrences during pregnancy, perimenopause and menopause. They are, in fact, the most common symptom of menopause.

They can be trigger or amplified by environmental factors, too. Alcohol, spicy foods, caffeine, nicotine, exercise, chocolate and fat can all trigger hot flashes.

A hot room, sleep deprivation, stress and medication can be other triggers.

Judy Caplan
Nutrition & Dietetics Specialist

Most women going through menopause experience hot flashes. Hot flash intensity is very individual. Some women have only a few while others experience them constantly throughout the day. Fluctuation in hormone levels can trigger hot flashes. In menopause estrogen levels are diminishing causing all kinds of symptoms, one of which are hot flashes. Alcohol, chocolate, exercise, coffee and overheated rooms can trigger a hot flash. Even stimulants like tea can set off a hot flash. Sometimes hot flashes come on for no apparent reason other than a woman is going through menopause. It is said that Asian women who eat a traditional Asian diet have fewer hot flashes.

Current theory suggests that the flushing, hot, tingling and sweating sensations during menopause may be due to a surge of the brain hormone gonadotropin-releasing hormone (GnRH), which has a direct effect on the part of the brain that regulates body temperature. This hormone is part of a group that controls ovarian hormone output. Normally, when ovaries are functioning at their reproductive levels, GnRH levels are low.

In menopausal women, the brain makes more of this hormone as a signal to the ovaries to return to their reproductive function. The increased GnRH resets the central heat regulatory center in the brain, which results in the blood vessels rapidly expanding in an attempt to reduce perceived overheating (vasodilation).

As menopause draws nearer, increasing amounts of hormones are released, causing increasingly severe symptoms, which can last up to five years if there is no estrogen replacement given, either by way of diet or medications.

Hot and humid weather, hot drinks, alcohol, stress, smoking, chocolate, spicy foods and foods with a high-acid content (e.g., citrus, tomatoes or strawberries) are all also known triggers of hot flashes during menopause.

Continue Learning about Menopause

What Are the Signs of Menopause?
What Are the Signs of Menopause?
Can Exercise Improve Hot Flashes?
Can Exercise Improve Hot Flashes?
Best Treatment for Menopause and Depression
Best Treatment for Menopause and Depression
Can a Proper Diet Help in Dealing with Hot Flashes?
Can a Proper Diet Help in Dealing with Hot Flashes?

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.