The Guide to Hot Flashes and Night Sweats
For many women, hot flashes and night sweats are one of the most annoying symptoms of menopause. These unpredictable spikes of heat always seem to come at the wrong moment, when you’re in a meeting, at a party, standing in the checkout line. You quickly peel your top layers off only to put them back on a few minutes later, wear summer clothing in the dead of winter, blast the air conditioning, freezing out your partner. Your hot flashes and night sweats wake you up during the night, and you start sleeping poorly, feeling a little like a zombie the next day. Sound familiar?
If you are experiencing hot flashes and night sweats in midlife, you are definitely not alone. Eighty percent of postmenopausal women have hot flashes, with about ten to twenty percent enduring severe hot flashes. It's not just older women who struggle with what is probably the most aggravating symptom of menopause, premenopausal and perimenopausal women get them too. In fact, hot flashes are usually the first symptom women experience during perimenopause, signaling that the menopause transition is underway. At some point in perimenopause, eighty-five percent of women will have hot flashes, and they get more frequent and intense from the early to late stages of perimenopause. Even young women who are premenopausal, about twenty-one percent, feel the heat.
Hot flash or something else?
Women taking birth control pills usually will not get hot flashes, but perimenopausal women will sometimes get them in the ‘pill-free’ week. Eliminating the pill free week by taking active pills every day makes this go away. Women whose hot flashes are not relieved by hormones may have another condition. Thyroid problems and diabetes or pre-diabetes are the most common conditions that can cause hot flash like symptoms. However, other rare conditions can also be present, along with autoimmune diseases and chronic infections that are causing sweating.
Hot Flashes and Ethnicity
The Study of Women’s Health Across the Nation (SWAN) is a large, multi-site longitudinal, epidemiological study designed to examine the health of women during the midlife years. It began in 1994 and is still running today. The SWAN study is particularly important because previous research was limited mainly to Caucasian women of northwestern European descent.
SWAN research has found that women of different ethnic/racial backgrounds experience hot flashes differently.
Japanese and Chinese women reported less severe hot flashes.
Hot flashes and night sweats were most frequently reported by African American women.
In a separate research study, the median total duration of hot flashes was 7.4 years. Of note, women who were premenopausal or in early perimenopause when they first reported frequent hot flashes had the longest total duration of hot flashes – more than 11.8 years. Compared to other racial/ethnic groups, African American women had the longest duration of hot flashes, with about half experiencing hot flashes for more than 10 years. Hispanic women had the second longest duration followed by Caucasian, Chinese, and Japanese women.
Hot Flash Science
Although their exact cause still isn’t fully understood, hot flashes are thought to be the result of changes in the hypothalamus, the part of the brain that regulates the body’s temperature. If the hypothalamus mistakenly senses that a woman is too warm, it starts a chain of events to cool her down. Blood vessels near the surface of the skin begin to dilate (enlarge), increasing blood flow to the surface in an attempt to dissipate body heat. This produces a red, flushed look to the face and neck in light-skinned women. It may also make a woman sweat to cool the body down. The heart may beat faster, and women may sense that rapid heartbeat. A cold chill often follows a hot flash. A few women experience only the chill. The hot flash sensation may last only a few seconds to a minute before it starts to subside.
There is good news on the horizon. Scientists have found that increased levels of a brain chemical called neurokinin B (NKB) may trigger hot flashes. This has led to the development of new experimental compounds that are thought to work by blocking the action of NKB and reducing hot flashes up to seventy-three percent. If the compound proves effective and safe in additional studies, it could replace hormone therapy as the standard pharmaceutical-based treatment for menopause symptoms. This would be especially beneficial for women who can’t take hormone therapy since the new drug would not have the side effects associated with estrogen.
Until science catches up, estrogen therapy is the mainstay for hot flash relief, with some non-hormonal alternatives that are not as effective as estrogen but may be preferable for many women. Later in this guide, I describe treatment options currently available for relieving hot flashes.
Hot Flash Triggers
There are certain things or events that can trigger hot flashes and play a role in their severity. Common causes are spicy food and alcohol. Others include sugar, caffeine, warm temperatures, hot baths, too heavy, too tight, or unbreathable synthetic clothing, being overweight, stress, anxiety, nervousness, or anger, and smoking. It helps to take note of what’s happing when a hot flash starts. By tracking your triggers, you can begin to make small lifestyle adjustments and reduce the frequency and intensity of hot flashes. Your record will also help to support the discussion you have with your doctor about options for managing hot flashes and night sweats.
5 Options for Relieving Hot Flashes and Night Sweats
It may feel like you have no control over hot flashes and night sweats, but that is not the case. There are several options available to reduce their frequency and intensity. They each have their pros and cons and not every woman, based on her medical history, is a candidate for using a particular option. Ideally, you should discuss these choices with a healthcare provider experienced in treating menopausal women.
In many cases, healthcare providers will recommend lifestyle changes before starting other treatment options like hormone therapy. Even if you are on hormone therapy, making changes to your lifestyle is still recommended to improve overall health and well-being in midlife. It’s important to take steps to reduce your risk of other serious conditions, including cardiovascular disease, dementia, and osteoporosis, all diseases that are linked to lifestyle and are more common in women than in men.
There are many lifestyle interventions that are effective in reducing the impact of hot flashes or delaying the onset if you are not yet experiencing hot flashes. They include diet and exercise, mind-body techniques, and self-care strategies. For example, a recent study found that sedentary women were twenty-one percent more likely to experience hot flashes. A study of women who engaged in vigorous exercise 4-5 days per week for 45 minutes a session said that their average frequency of hot flashes declined by more than sixty percent. Another study showed that women who reported exercising every day were forty-nine percent less likely to report bothersome hot flashes. Women whose exercise level decreased were more likely to experience bothersome hot flashes. There are a few studies that show exercise may exacerbate hot flashes.
Many physicians don’t view lifestyle medicine as part of their job and it’s not a standard part of their training. They are also under pressure to see many patients each day and may not have the time to spend with women on education and creating a comprehensive lifestyle plan. A recent survey by the North American Menopause Society and Gallup found that only two percent of physicians discuss lifestyle interventions with menopausal women. If you want to try lifestyle changes to manage your symptoms, you may need to find a healthcare practitioner or other resource specializing in lifestyle medicine that can support you.
Hormones can be effective in treating hot flashes. Hormone therapy balances estrogen and progesterone levels in the body. The standard recommendation from the North American Menopause Society is that hormone therapy should be prescribed at the lowest dose, for the shortest period of time it remains effective - five years or less, for women up to age 59 or within 10 years of reaching menopause. The risks increase the further out you get from menopause and with advancing age.
Hormone therapy products include conjugated equine estrogens (CEE), which is extracted from the urine of pregnant mares, and bioidentical options. There are many Food and Drug Administration (FDA)-approved options - pills, patches, gels, and sprays - that come in combinations of estrogen and progesterone (for women with a uterus) and estrogen alone (for women without a uterus). Make sure your doctor is knowledgeable about the different options and can help you determine which one is right for you.
Bioidentical hormones are synthesized by chemically extracting diosgenin from plants such as yams and soy. Some women prefer plant-based hormones. However, all hormone therapy products undergo extensive chemical processing and modification.
Compounded therapy combines ratios of bioidentical hormones into a particular recipe or mixture. Custom-prepared mixtures of different bioidentical hormones are not regulated by the FDA and are not considered safe. There is no guarantee that the ingredients have been tested for purity, potency, and effectiveness. To date, no scientific evidence is available to show that these compounded therapies are safer or more effective than government-approved hormones. In 2012, More magazine completed an investigative report of bioidentical hormones produced by 12 compounding pharmacies nationwide. The conclusion was that women may be putting their health at risk. However, some women may have no other alternative to compounding because of an allergy. If you decide to use a compounding pharmacy, for whatever reason, check whether the company is accredited by the Pharmacy Compounding Accreditation Board.
Bioidentical hormone therapy does not have to be custom mixed. The FDA has approved some bioidentical hormone products. Most recently, a new drug called Bijuva was approved to treat hot flashes for women who still have their uterus. The new drug still comes with a warning about side effects similar to other hormone therapy products. Bijuva is expected to be available through physicians in spring 2019 and will be covered by insurance.
Hormone therapy is not without risks, and the decision to start hormone therapy should be made with your doctor. Both estrogen therapy and estrogen with progestogen therapy increase the risk of blood clots in the legs and lungs, similar to birth control pills, patches, and rings. Although the risks of blood clots and strokes increase with either type of hormone therapy, the risk is rare in the 50 to 59 age group. An increased risk in breast cancer is seen with five or more years of continuous estrogen/progestogen therapy, possibly earlier. The risk decreases after hormone therapy is stopped. Use of estrogen alone for an average of seven years in the Women’s Health Initiative trial did not increase the risk of breast cancer. Women who have had any of these conditions should not use hormone therapy.
Certain kinds of cancers, like breast cancer or uterine cancer
History of stroke or heart attack, or a strong family history of stroke or heart disease
Problems with vaginal bleeding or have a bleeding disorder
Pregnant or may become pregnant
Allergic reactions to hormone medications
Paroxetine (Brisdelle)—a selective serotonin reuptake inhibitor (SSRI) also used to treat depression—is the only non-hormonal medication approved by the FDA for managing hot flashes.
Two other prescription medications, gabapentin (Neurontin)—a drug for chronic nerve pain—and clonidine (Catapres)—a blood pressure drug—are sometimes prescribed for hot flashes but are not FDA-approved for this use.
The consensus among the medical community is that more research is needed to determine the safety and effectiveness of herbal treatments. However, many women still try various remedies in the hope that they will find relief from hot flashes and other menopause symptoms. If you decide to try an herbal remedy, make sure you understand the potential health risks and interactions with other medications you may be taking.
Black cohosh is the most widely studied of the herbal remedies. The studies have produced mixed results although some women report black cohosh has helped them. There is some concern that blue cohosh (not black cohosh) may be associated with liver damage. It is not known for sure if blue cohosh actually causes liver damage. Black cohosh also interacts with many prescribed medications and should not be used at the same time as other herbs. According to the National Center for Complementary and Alternative Medicine, some commercial black cohosh products have been found to contain the wrong herb or to contain mixtures of black cohosh and other herbs that are not listed on the label.
Red clover has had no consistent or conclusive evidence in controlled studies that it was found to reduce hot flashes. As with black cohosh, some women claim that red clover has helped them. Studies report few side effects and no serious health problems with use. But studies in animals have raised concerns that red clover might have harmful effects on hormone-sensitive tissue.
Dong quai has been used in Traditional Chinese Medicine to treat gynecologic conditions for more than 1,200 years. Yet only one randomized clinical study of dong quai has been conducted to determine its effects on hot flashes, and this herbal remedy was not found to be useful in reducing them. The North American Menopause Society states that dong quai should never be used by women with fibroids or blood-clotting problems such as hemophilia, or by women taking drugs that affect clotting such as warfarin (Coumadin) as bleeding complications can result.
Evening primrose oil is also said to relieve hot flashes. However, the only study to date found no benefit. Reported side effects include inflammation, problems with blood clotting and the immune system, nausea, and diarrhea. It has been shown to induce seizures in patients diagnosed with schizophrenia who are taking antipsychotic medication. Evening primrose oil should not be used with anticoagulants or phenothiazines (a type of psychotherapeutic agent).
Phytoestrogens are estrogen-like substances found in some cereals, vegetables, and legumes (like soy), and herbs. They have not been consistently shown to be effective in studies, and their long-term safety is unclear.
Valerian Root contains phytoestrogens, and a small study found it to be effective in reducing the frequency and intensity of hot flashes. However, phytoestrogens are controversial, and researchers recommend additional research to confirm the safety and effectiveness of phytoestrogen-based herbal remedies. Valerian is also believed to help with sleep, but the evidence is inconsistent.
Licorice Root was evaluated for hot flash relief in a small study where it was found to relieve the frequency and intensity of hot flashes. In large amounts and with long-term use, licorice root can cause high blood pressure and low potassium levels, which could lead to heart and muscle problems. More research is needed to determine its effectiveness and safety for hot flashes.
Fortunately for women, new companies, many founded and led by women, are tackling a variety of women’s health issues with modern technology. Embr Wave is a wristwatch-like device that can help cool you down or warm you up at the touch of a button. Embr wasn’t originally designed to relieve hot flashes, but the company found that women battling hot flashes were buying the device and finding some relief. In a recent study, eighty-nine percent of all users (not just women with hot flashes) reported feeling more comfortable.
The most important takeaway from this article is that there are many options at your disposal to reduce the severity and intensity of hot flashes and night sweats. You do not have to suffer from inconvenient and uncomfortable swings in body temperature that impact your sleep, mood, and quality of life. Talk to your healthcare provider about the options we’ve outlined. If your provider doesn’t seem knowledgeable or doesn’t take the time to explain these options, search the North American Menopause Society’s database for a certified menopause practitioner in your area. You deserve to have a healthcare provider that understands this complex and challenging period in your life and can support you to feel your best every day.
Dr. Nanette Santoro is a leading clinician and researcher in Reproductive Endocrinology. She is currently Professor and E Stewart Taylor Chair of Obstetrics & Gynecology at the University of Colorado School of Medicine. She also directed the Division of Reproductive Endocrinology at 2 medical schools: New Jersey Medical School and the Albert Einstein College of Medicine. She is the author of over 120 scientific publications and two books. Dr. Santoro’s major research interests include the reproductive endocrinology of premature, peri-, and postmenopause, infertility, and the physiology of gonadotropin-releasing hormone secretion. She has been involved with numerous large-scale industry- and government-supported clinical trials, including the Study of Women’s Health Across the Nation (SWAN), the Kronos Early Estrogen Prevention Study (KEEPS), and the Reproductive Physiology of Ovarian Failure, and is a co-editor of the Textbook of Perimenopausal Gynecology. Dr. Santoro received her medical degree at Albany Medical College and completed her residency at Beth Israel Medical Center and fellowship at Massachusetts General Hospital, Harvard Medical School.
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