Hot flashes definition and facts
- Hot flashes are feelings of warmth that spread over the body and last from 30 seconds to a few minutes.
- Hot flashes may be accompanied by redness of the skin, known as flushing, and excessive sweating.
- Hot flashes are a characteristic symptom of the menopausal transition (perimenopause, menopause, and postmenopause) in women, but may occasionally result from other medical conditions.
- About 70% of women will experience hot flashes at some point in the menopausal transition.
- Hot flashes in men, young women, or during pregnancy may be due to medical conditions that interfere with the body’s ability regulate temperature.
- Hot flashes may be treated by hormone therapy or other medications if necessary.
- Natural home remedies for hot flashes have been proposed and may provide relief for some women; the effectiveness of other alternative treatments has not been adequately scientifically evaluated.
What are hot flashes?
A hot flash is a sensation of heat that begins in the head and neck regions. Hot flashes are a common symptom experienced by women prior to, and during the early stages of the menopausal transition. However, not all women approaching the menopause will develop hot flashes.
How long do hot flashes last?
Hot flashes are typically brief, lasting from about 30 seconds to a few minutes.
The question of how long during a woman's lifetime that hot flashes last is a different one. Traditionally, it was believed that women only experienced hot flashes for a few years. More recent data suggest that many women may experience hot flashes for longer time periods. In a study from the University of Pennsylvania, the mean duration of hot flashes was 4.9 years, but up to a third of women continued to have hot flashes for up to 10 years. In the Study of Women Across the Nation (SWAN), women had hot flashes for an average of 7.4 years total and for an average of 4.5 years after the last menstrual period.
What causes hot flashes?
The complex hormonal changes that accompany the aging process, in particular the declining levels of estrogen as a woman approaches menopause, are thought to be the underlying cause of hot flashes. A disorder in thermoregulation (methods the body uses to control and regulate body temperature) is responsible for the heat sensation, but the exact way in which the changing hormone levels affect thermoregulation is not fully understood.
Hot flashes are considered to be a characteristic symptom of the menopausal transition. They also occur in men and in circumstances other than the perimenopause in women (such as young women or during pregnancy) as a result of certain uncommon medical conditions that affect the process of thermoregulation. For example, the carcinoid syndrome, which results from a type of endocrine tumor that secretes large amounts of the hormone serotonin can cause hot flashes. Hot flashes can also develop as a side effect of some medications and sometimes occur with severe infections or cancers that may be associated with fevers and/or night sweats.
Signs and symptoms: What do hot flashes feel like?
- Hot flashes are typically brief, lasting from about 30 seconds to a few minutes.
- Redness of the skin, known as flushing, may accompany hot flashes.
- Excessive perspiration (sweating) can also occur; when hot flashes occur during sleep they may be accompanied by night sweats.
- Feelings of anxiety may accompany hot flashes.
- Occasionally, palpitations (feelings of a racing heart beat) may occur during hot flashes.
The timing of the onset of hot flashes in women approaching menopause is variable.
- While not all women will experience hot flashes, many normally menstruating women will begin experiencing hot flashes even several years prior to the cessation of menstrual periods.
- It is impossible to predict if a woman will experience hot flashes, and if she does, when they will begin.
- About 40% to 85% of women experience hot flashes at some point in the menopausal transition.
How is the cause of hot flashes diagnosed?
Hot flashes are a symptom, not a medical condition. Taking a thorough medical history, the health-care professional will usually be able to determine whether a woman is having hot flashes. The patient will be asked to describe the hot flashes, including how often and when they occur, and if there are other associated symptoms. A physical examination together with the medical history can help determine the cause of the hot flashes and direct further testing if necessary.
Blood tests may be performed if the diagnosis is unclear, either to measure hormone levels or to look for signs of other conditions (such as infection) that could be responsible for the hot flashes.
Perimenopause Symptoms and Signs
Perimenopause describes the time period when a woman is approaching menopause. During this time is when symptoms and signs begin. Examples include, weight gain, vaginal dryness, mood changes, painful sex, and hot flashes.
What are the treatments for hot flashes?
There are a variety of treatments for hot flashes such as:
Some of these have not been tested by clinical studies, nor are they approved by the US Food and Drug Administration (FDA).
Hormone therapy for hot flashes
Traditionally, hot flashes have been treated with either oral or transdermal (such as a patch) forms of estrogen. Hormone therapy (HT) or postmenopausal hormone therapy (PHT), formerly referred to as hormone replacement therapy (HRT), consists of estrogens alone or a combination of estrogens and progesterone (progestin). All available prescription estrogen medications, whether oral or transdermal, are effective in reducing the frequency of hot flashes and their severity. Research indicates that these medications decrease the frequency of hot flashes.
However, long-term studies (the NIH-sponsored Women's Health Initiative, or WHI) of women receiving combined hormone therapy with both estrogen and progesterone were halted when it was discovered that these women had an increased risk for heart attack, stroke, and breast cancer when compared with women who did not receive hormone therapy. Later studies of women taking estrogen therapy alone showed that estrogen was associated with an increased risk for stroke, but not for heart attack or breast cancer. Estrogen therapy alone, however, is associated with an increased risk of developing endometrial cancer (cancer of the lining of the uterus) in postmenopausal women who have not had their uterus surgically removed.
More recently, it has been noted that the negative effects associated with hormone therapy were described in older women who were years beyond menopause, and some researchers have suggested that these negative outcomes might be lessened or prevented if hormone therapy was given to younger women (prior to or around the age of menopause) instead of women years beyond menopause.
The decision in regard to starting or continuing hormone therapy, therefore, is an individual one in which the patient and doctor must take into account the inherent risks and benefits of the treatment along with each woman's own medical history. It is currently recommended that if hormone therapy is used, it should be used at the smallest effective dose for the shortest possible time.
Bioidentical hormone therapy for hot flashes
There has been increasing interest in recent years in the use of so-called "bioidentical" hormone therapy for perimenopausal women. Bioidentical hormone preparations are medications that contain hormones that have the same chemical formula as those made naturally in the body. The hormones are created in a laboratory by altering compounds derived from naturally-occurring plant products. Some of these so-called bioidentical hormone preparations are U.S. FDA-approved and manufactured by drug companies, while others are made at special pharmacies called compounding pharmacies, which make the preparations on a case-by-case basis for each patient. These individual preparations are not regulated by the FDA, because compounded products are not standardized.
Advocates of bioidentical hormone therapy argue that the products, applied as creams or gels, are absorbed into the body in their active form without the need for "first pass" metabolism in the liver, and that their use may avoid potentially dangerous side effects of synthetic hormones used in conventional hormone therapy. However, studies to establish the long-term safety and effectiveness of these products have not been carried out.
Menopause & Perimenopause: Symptoms, Signs
Other prescription drug treatments for hot flashes
- The selective serotonin reuptake inhibitor (SSRI) medications have been shown be effective in reducing menopausal hot flashes. These drugs are generally used in the treatment of depression and anxiety as well as other condition. Paroxetine (Brisdelle) is an SSRI approved to treat moderate to severe hot flashes associated with menopause.
- Clonidine (Catapres) is an anti-hypertensive drug that can relieve hot flashes in some women. Clonidine is taken either by pill or skin patch and decreases blood pressure. Side effects of clonidine can include dry mouth, constipation, drowsiness, or difficulty sleeping.
- Gabapentin (Neurontin), a drug primarily used for the treatment of seizures, has also been effective in treating hot flashes.
- Megestrol acetate (Megace) is a progestin that is sometimes prescribed over a short-term to help relieve hot flashes, but this drug is not usually recommended as a first-line treatment for hot flashes. Serious side effects can occur if the medication is abruptly discontinued. Megestrol may have the side effect of weight gain.
- Medroxyprogesterone acetate (Depo-Provera) is another progestin drug and is administered by injection to treat hot flashes. It may lead to weight gain as well as bone loss.
What natural and home remedies treat hot flashes?
Some women report that exercise programs or relaxation methods have helped to control hot flashes, but controlled studies have failed to show a benefit of these practices in relieving the symptoms of hot flashes. Maintaining a cool sleep environment and the use of cotton bedclothes can help ease some of the discomfort associated with hot flashes and associated night sweats.
Many women turn to alternative therapies, including herbal products, vitamins, plant estrogens, and other substances, for the treatment of hot flashes. Doctors can be reluctant to recommend alternative treatments because these nonprescription products are not regulated by the FDA (like prescription medications), and their ingredients and strength can vary from manufacturer to manufacturer. For products that are not regulated by the FDA, testing and proof of safety is not required for marketing of these products. Long-term, scientifically controlled studies for these products are either lacking or have not proved the safely and effectiveness of many of the so-called natural or alternative remedies.
Some alternative treatments, however, have been evaluated in well-designed clinical trials. Alternative treatments that have been scientifically studied with some research include phytoestrogens (plant estrogens, isoflavones), black cohosh, and vitamin E.
Black cohosh for hot flashes
Black cohosh is an herbal preparation that is becoming more and more popular in the U.S., and the North American Menopause Society does support the short-term use of black cohosh for treating menopausal symptoms, for a period of up to six months (because of its relatively low incidence of side effects when used over the short-term).
Some studies have shown that black cohosh can reduce hot flashes, but most of the studies have not been considered to be rigorous enough in their design to firmly prove any benefit. There also have not been scientific studies done to establish the long-term benefits and safety of this product. Research is ongoing to further determine the effectiveness and safety of black cohosh.
Soy and other plant sources for menopause symptoms
Isoflavones are chemical compounds found in soy and other plants (such as chick peas and lentils) that are phytoestrogens, or plant-derived estrogens. They have a chemical structure that is similar to the estrogens naturally produced by the body, but their effectiveness as an estrogen has been determined to be much lower than true estrogens.
Some studies have shown that these compounds may help relieve hot flashes and other symptoms of menopause. In particular, women who have had breast cancer and do not want to take hormone therapy (HT) with estrogen sometimes use soy products for relief of menopausal symptoms. However, some phytoestrogens can actually have anti-estrogenic properties in certain situations, and the overall risks of these preparations have not yet been determined.
There is also a perception among many women that plant estrogens are "natural" and therefore safer than hormone therapy, but this has never been proven scientifically. Further research is needed to fully characterize the safety and potential risks of phytoestrogens.
Other vitamins, herbs, and supplements
There are many other supplements and substances that have been used as treatments for symptoms of menopause such as hot flashes, including:
For more information please read our Alternative Treatments for Hot Flashes article.
Scientific studies to prove the safety and effectiveness of these products in relieving hot flashes have not been adequately performed.
Which type of doctor treats hot flashes?
Many women will consult their gynecologist for the management of hot flashes associated with approaching menopause. Hot flashes are also treated by primary care providers, including internists and family practitioners. Hot flashes related to uncommon conditions, serious infections, or cancers are treated by the specialists treating the underlying condition.
Can hot flashes be prevented?
While the development of hot flashes cannot be prevented, the treatment methods as described in the above section may be able to reduce their incidence and severity.
If menopause occurs in a woman younger than ___ years, it is considered to be premature.
Santen, Richard J, MD, et al. "Menopausal hot flashes." UptoDate. Mar 17, 2015