If you've had one, there's no mistaking it: the sudden, intense, hot feeling on your face and upper body, perhaps preceded or accompanied by a rapid heartbeat and sweating, nausea, dizziness, anxiety, headache, weakness, or a feeling of suffocation. Some women experience an "aura," an uneasy feeling just before the hot flash that lets them know what's coming. The flash is followed by a flush, leaving you reddened and perspiring. You can have a soaker or merely a moist upper lip. A chill can lead off the episode or be the finale.
Learn about the other symptoms of menopause in the Managing Menopausal Symptoms section.
What causes them
Hot flashes are mostly caused by the hormonal changes of menopause, but can also be affected by lifestyle and medications. A diminished level of estrogen has a direct effect on the hypothalamus, the part of the brain responsible for controlling your appetite, sleep cycles, sex hormones, and body temperature. Somehow (we don't know how), the drop in estrogen confuses the hypothalamus — which is sometimes referred to as the body's "thermostat" — and makes it read "too hot."
The brain responds to this report by broadcasting an all-out alert to the heart, blood vessels, and nervous system: "Get rid of the heat!" The message is transmitted by the nervous system's chemical messenger, epinephrine, and related compounds: norepinephrine, prostaglandin, serotonin. The message is delivered instantly. Your heart pumps faster, the blood vessels in your skin dilate to circulate more blood to radiate off the heat, and your sweat glands release sweat to cool you off even more.
This heat-releasing mechanism is how your body keeps you from overheating in the summer, but when the process is triggered instead by a drop in estrogen, your brain's confused response can make you very uncomfortable. Some women's skin temperature can rise six degrees Centigrade during a hot flash. Your body cools down when it shouldn't, and you are miserable: soaking wet in the middle of a board meeting or in the middle of a good night's sleep.
Who gets them
Eighty-five percent of the women in the United States experience hot flashes of some kind as they approach menopause and for the first year or two after their periods stop. Between 20 and 50% of women continue to have them for many more years. As time goes on, the intensity decreases.
If you have had breast cancer, your hot flashes can follow the same pattern as for women in general, or they can be more intense and last longer, particularly if menopause was premature, or if you are taking hormonal therapy and your body hasn't adjusted to it. Rarely, women may not have hot flashes until they stop taking tamoxifen — an unpleasant surprise. In these women, tamoxifen develops an unusual estrogen-like ability to combat hot flashes.
There is considerable variation in time of onset, duration, frequency, and the nature of hot flashes, whether you've had breast cancer or not. An episode can last a few seconds or a few minutes, occasionally even an hour, but it can take another half hour for you to feel yourself again. The most common time of onset is between six and eight in the morning, and between six to ten at night.
How hot is hot?
Most women have mild to moderate hot flashes, but about 10–15% of women experience such severe hot flashes that they seek medical attention. For women who have had breast cancer, the number who suffer debilitating hot flashes is probably much higher. Randomized studies provide the most objective data: about 50–75% of women taking tamoxifen will report hot flashes, compared to 25–50% taking placebo.
The faster you go through the transition from regular periods to no periods — the perimenopause or climacteric — the more significant your hot flashes will be. Hot flashes are severe after surgical menopause, and they can also be quite difficult after a chemotherapy-induced medical menopause. If you haven't been warned about hot flashes, a sudden severe episode can be frightening; you might even confuse the flash with a heart attack.
The intensity of hot flashes accompanying treatment with tamoxifen eventually improves for many women after the first three to six months. Because of the conversion of androstenedione from the adrenal glands into estrone by fat and muscle cells, heavy or muscular women experience less severe hot flashes than thin women. If you smoke, your blood vessels lose some of their ability to radiate heat, so you may suffer more severe hot flashes.
Beating the heat naturally
The best way to beat a hot flash is naturally. Hot flashes have a lot to do with the low levels of estrogen in your body, but other factors can cause your temperature control to go out of whack. Studies show that medication is not always helpful. Instead of taking HRT, which can increase breast cancer risk and isn't recommended for women who've been diagnosed with breast cancer, look at less drastic measures first because you should always begin with the least aggressive approach to treat menopausal symptoms.
If you can identify the things that trigger your hot flashes, you've made the first step in getting the upper hand. Keep a record of when they occur and what you were eating or doing, or how you were feeling at the time. Many women find that stress tops the charts as a trigger. Was that hot flash in the boardroom a random hit, or were you feeling under pressure at the time? Was it a full day of pressure without a break?
Solution: Ease the pressure. Give yourself more time to plan your work, to rehearse your presentation, to deliver your assignments, to arrive where you're going. If you are doing a series of presentations, give yourself a chance to relax and cool off between sessions. And plan your schedule so you avoid meetings or decision making when you're most likely to be in a sweat.
Other hot flash triggers:
Hot flash survival tips
- Dress in layers, so you can peel off one layer after another as you get warmer.
- Don't wear wool, don't wear synthetics, and be wary of silk. That leaves cotton, linen, rayon, and more cotton. (Look at the bright side: You'll save on cleaning bills, and you can stop worrying about moths.)
- Avoid turtlenecks. Stick to open-neck shirts.
- Keep ice water at hand that you can sip to cool down your insides.
- Where possible, lower the thermostat. Maybe it's time for a decent air conditioner or a ceiling fan. Or maybe you'd prefer one of those little hand-held battery-operated fans or the foldable kind you flutter in front of your face. You can find perfectly adequate paper fans for about a dollar.
- Wear cotton pajamas or a nightgown. If you perspire a lot at night, your nightclothes are easier to change than the sheets.
- Use cotton sheets only, not synthetics.
- Get a bigger bed if you and your partner are on different heat planets but you still want to stay in close orbit.
- Take a cool shower before bed.
- Try a mild medication like Tylenol
- Arrive at meetings early so that you can get the coolest seat.
- Use your freezer liberally. A number of women talked about opening the freezer at home (or in the supermarket) and sticking their head in when a hot flash hits.
Lifestyle changes to alleviate hot flashes
Increasing your level of activity (for example, taking the stairs instead of the elevator) can reduce hot flashes and have a positive impact on just about every other symptom attributed to menopause and growing older, including:
Exercise also increases endorphin levels, increasing your threshold for pain.
Relaxation and stress reduction
It isn't unusual to have trouble dealing with stress, especially if you've undergone treatment for breast cancer. You may find that one of the following techniques will help you minimize the devastating effects of stress on your body:
Changing your diet
Over time, a low-fat diet helps some women with hot flashes. Losing excess weight helps, but losing too much weight, or being too thin, can worsen symptoms. As you consider other food changes, keep in mind that natural doesn't mean harmless. Herbal remedies and soy preparations may work because of their plant estrogens, but you can't assume that just because an estrogen comes from a plant it's a safe remedy.
Chinese medicine has a long tradition of treating hot flashes. There are all kinds of hot flashes, and the Chinese have descriptions for all of them. Before treating you, a Chinese doctor takes a full history and performs a complete physical, with particular attention to your tongue and your pulse. He or she then determines whether you're suffering from a "hot" menopause or a "cold" menopause. If you have gone through a surgical or medical menopause, Chinese herbs are usually not considered strong enough to eliminate your menopausal hot flashes, but they can help.
Chinese medicine usually involves:
- acupuncture, which moves your Xi (your inner wind, energy, or spirit). For every woman who's skeptical about this approach, there's a woman who's found acupuncture helpful for hot flashes.
- herbology, in which many different herbs are cooked together to make a tea customized to your particular symptoms. Common to all Chinese herbal mixes is dong quai, thought to be a plant estrogen. More plant estrogens that women have found effective in treating hot flashes over the centuries can be found in ginseng, evening primrose oil, licorice root, red raspberry leaves, sarsaparilla, spearmint, damiana, motherwort, chasteberry (also known as Vitex), black cohosh, and wild yams. These herbal remedies, Chinese and other, may be effective at reducing hot flashes but, again, their relative safety in women who have had breast cancer is not known. Avoiding, or using plant estrogens with great caution, is best, and never try them without telling your doctor. Even leading Chinese medicine practitioners caution women not to self-treat with Chinese herbs.
Some women find that taking vitamin E every day (800 I.U., range 400–1000) helps. Actually, a placebo works almost as well. The National Cancer Institute's/National Surgical Adjuvant Breast and Bowel Project's Tamoxifen Breast Cancer Prevention Trial also recommends vitamin E, or one of the following: vitamin B6, 200–250 milligrams daily, and Peridin-C (containing antioxidants), two tablets taken three times daily. If vitamin E helps you, great, but if you have significant hot flashes, you will probably need something more effective.
Relieving hot flashes with medications
If you have tried these lifestyle, nutritional, and alternative medicine recommendations, and they have not helped, you may feel compelled to go on to stronger remedies, available only through your physician.
Blood pressure-lowering medication
Blood pressure-lowering medications such as clonidine (Catapres-TTS, 0.1–mg patch applied once weekly) and Aldomet (250 mg twice daily) can lessen the severity and frequency of hot flashes. They modify how the blood vessels respond to the brain's command to give off heat quickly. These drugs must be prescribed and adjusted carefully by your doctor.
Low-dose antidepressant medication may help forestall a hot flash by rebalancing or intercepting the chemicals in the brain that transmit the hot flash alarm, epinephrine and serotonin.
Effexor (venlafaxine) can reduce hot flashes by about 50% in nearly 60% of women with breast cancer according to a study done by Dr. Charles Loprinzi at the Mayo Clinic. Improvement happened relatively quickly: 80% of the eventual decrease in hot flashes occurred within the first week of taking the medication. Side effects, when they were noted, were mild. The dose used was 12.5 milligrams taken twice daily.
A more recent study showed that some women may need a higher total dose of 75 milligrams daily to get significant relief. Extended-release preparations are available. Paxil (paroxetine) works in a similar way to Effexor and is a good alternative. Some women tolerate Paxil better. Its recommended dose is 10 mg once a day for the first week, then 20 mg once a day thereafter.
If you are taking tamoxifen, talk to your doctor about which antidepressants are safe for you to take to manage hot flashes. Some antidepressants — including Paxil, Wellbutrin (chemical name: bupropion), Prozac (chemical name: fluoxetine), Cymbalta (chemical name: duloxetine), and Zoloft (chemical name: sertraline) — interfere with the body's ability to convert tamoxifen into its active form, preventing you from getting the full benefit of tamoxifen. For more information, please visit the Tamoxifen page.
Bellergal-S simmers down overactive chemical activity in the brain. Taken occasionally, once or twice a day, it can be quite safe and effective — but not with alcohol. (It contains belladonna, phenobarbital, and an ergotamine.) Phenobarbital can cause drowsiness and, if you use it regularly, you can develop a dependency for it.
Megace (megesterol acetate) can reduce hot flashes in approximately 80% of women who take it, and it is also considered a treatment for breast cancer when taken in high doses continuously. Megace is usually started at 40 milligrams daily, and it may take a few weeks to start to work. After a month the dose is adjusted up or down. The maximum dose is 80 milligrams per day. Those who reap its benefits and can tolerate its side effects (fluid retention and bloating) may do well on this medication.
Hormone replacement therapy (HRT)
While hormone replacement therapy (HRT) can ease menopausal symptoms, such as hot flashes and fatigue, current or recent past users of HRT have a higher risk of being diagnosed with breast cancer.
Before the link between HRT use and breast cancer risk was established, many postmenopausal women took HRT for many years to ease menopausal symptoms and to reduce bone loss. Since 2002, when research linked HRT and risk, the number of women taking HRT has dropped dramatically. Still, many women continue to use HRT to handle bothersome menopausal symptoms.
There are two main types of HRT:
- combination HRT contains the hormones estrogen and progesterone
- estrogen-only HRT contains only estrogen
Research has found that:
- breast cancer risk goes up in the first several years of HRT use; risk seems to keep increasing the longer a woman uses HRT
- both combination HRT and estrogen-only HRT increase breast cancer risk, but combination HRT increases risk more
- high-dose HRT increases risk more than low-dose HRT
The higher breast cancer risk from using HRT is the same for so-called "bioidentical" and "natural" hormones as it is for synthetic hormones. "Bioidentical" means the hormones in the product are identical to the hormones your body produces. Bioidentical hormones are said to be "natural" — derived from plants. Synthetic hormones are made in a lab and are also chemically identical to the hormones in your body. It's important to know that many herbal and bioidentical HRT products fall outside the jurisdiction of the United States Food and Drug Administration and so aren't subject to the same regulations and testing that medications are.
Menopausal side effects can dramatically reduce quality of life for some women. These women have to weigh the benefits of HRT against the risks. If you're having severe hot flashes or other menopausal side effects and are considering HRT, talk to your doctor about ALL of your options. Ask how you can minimize your breast cancer risk AND relieve your symptoms. Be sure to discuss the pros and cons of different types and doses of HRT.
Research strongly suggests that estrogen-only HRT appears to increase breast cancer risk less than combination HRT. If you do decide to take HRT, ask if you can take a lower-dose formula and talk to your doctor about taking it for the shortest time possible.
If you've been diagnosed with breast cancer or have tested positive for an abnormal breast cancer gene (BRCA1 or BRCA2) and so are at high risk, you shouldn't use HRT. The hormones in HRT can cause hormone-receptor-positive breast cancers to develop and grow. While only a few small studies have looked at HRT use in women with a personal history of breast cancer, the fact that HRT use increases breast cancer risk among women in general makes almost all doctors advise women with a personal history of breast cancer to avoid HRT. The prescribing sheet included with HRT clearly states that it is "contraindicated in women with a diagnosis of breast cancer." Not being able to use HRT can present a challenge for many women. If you're having severe hot flashes or other menopausal side effects and have a personal history of breast cancer, talk to your doctor about non-hormonal options, such as dietary changes, exercise, weight management, acupuncture, or meditation.
For more information on HRT and breast cancer risk, visit the Using HRT page in the Breastcancer.org Lower Your Risk section.