Hot Flashes and Night Sweats

By OBOS Menopause Contributors | October 15, 2011

Hot flashes are legendary signs of perimenopause and menopause. A woman experiencing a hot flash will suddenly feel warm, then very hot and sweaty, and sometimes experience a cold chill afterward.

Hot flashes are thought to be due to a change in the brain’s control mechanism for body temperature. Some women experience a more rapid pulse rate, a feeling that the heart is jumping (palpitations), or increased or decreased blood pressure. There is increased blood flow to surface blood vessels, so the hands get hot, and sometimes there is a visible reddening of the skin that moves from the chest up to the face. Some women feel panicky.

Hot flashes may begin long before cycles become irregular; you may start to feel warmer at night before other changes begin. They may even occur around your period or after childbirth.

For some women, hot flashes continue for years after their last period: 45 percent of women still have them five to 10 years after periods stop, and a small number of women have them into their 70s. About 20 to 30 percent of women never have them at all.

Each woman has her own hot-flash script: the frequency; the triggers; how the hot flash starts and finishes; how often flashes come; and how long they last. An occasional mild hot flash may be easy to ignore, but some women find flashes acutely uncomfortable, distracting, and even embarrassing.

Hot flashes sometimes cause enough perspiration to soak nightclothes and sheets (night sweats), and they can disturb sleep.

Women who are heavier tend to experience more frequent and more severe hot flashes than thinner women, because the increased subcutaneous tissue acts as insulation and prevents heat loss. Hot flashes are the body’s attempt to get rid of heat, and those of us who are better insulated often have more difficulty doing so.

Strategies to Reduce Discomfort

Here are some strategies that may help reduce the discomfort of hot flashes:

  • Dress in layers (especially breathable or natural fibers), so you can shed or add clothes according to how you are feeling.
  • Identify your personal triggers, and attempt to avoid them. Spicy foods, hot drinks, alcohol, caffeine, and anxiety are common triggers.
  • Carry cool water with you and drink it regularly. Keep your environment cool with fans or air-conditioning.
  • Learn to decrease your response to stress through, for example, meditation, or by practicing slow, deep abdominal breathing several times a day. When a flash starts, use the slow breathing method.
  • Do something active that increases your heart rate for 30 minutes a day.
  • Try putting a cold pack under your pillow at night so when you wake up with a hot flash you can turn your pillow over and it is nice and cool.
  • Wash your hands in cool water at the start of or after a hot flash; it will cool you off and make you feel cleaner.
  • If you are a smoker, get help in quitting. Smokers tend to have more frequent and more intense hot flashes.

In the past, the primary treatment for hot flashes and night sweats (called vasomotor symptoms) was estrogen-plus-progestin hormone therapy (also called hormone replacement therapy). Hormone therapy is very effective at reducing both the frequency and severity of hot flashes.

Unfortunately, as the Women’s Health Initiative (WHI) trials demonstrated, the long-term use of this hormone regimen increases the risk of heart disease, stroke, blood clots and breast cancer.

Recent research indicates that the benefits and harms of hormones may depend on the type of hormone, who’s using it, in what form, and when. Additional research is needed to best understand the most effective and safest use.

Until such research is done, women who take hormone therapy are advised to use the smallest dose that effectively treats their hot flashes for the shortest amount of time possible.

Nonhormonal Medications

There are various nonhormonal medications that women have tried for problematic hot flashes. Keep in mind that there is no evidence at this point that using any of the nonhormonal medications for months or years is safer than hormone therapy.

Antidepressants. Studies have indicated that relatively low doses of some antidepressants can be more effective at preventing hot flashes than a placebo (and about 70 percent as effective as estrogen). The drug tested most extensively has been low-dose venlafaxine (Effexor), although others such as paroxetine (Paxil) and fluoxetine (Prozac) also seem to work. However, there is no long-term safety data on such use.

In addition, the studies producing the most positive results were conducted with women who had breast cancer, and negative results were reported more often by women without breast cancer. Further study on women without breast cancer is needed.

Antidepressants are perhaps most appropriate for hot flashes if you also need treatment for depression. They come with their own unknowns and potential side effects, including sleep difficulties, lowered sexual interest, and difficulty reaching orgasm, and some women have difficulty when they try to stop taking them.

Gabapentin. A seizure medication used for pain control, gabapentin has been used with some success to treat hot flashes, but it, too, has side effects to consider, including nausea and fatigue. It is often most appropriate for hot flashes in women who also need the medication for pain.

Clonidine. The antihypertensive clonidine has also been used to treat hot flashes. Antihypertensives are perhaps most appropriate for hot flashes if you also need treatment for high blood pressure. If this treatment is taken in doses that are effective, women without high blood pressure may experience dizziness or dry mouth.

New methods. There have been reports of success in treating recalcitrant (stubborn) hot flashes using a nerve block in the neck (stellate ganglion block), although this more invasive approach demands caution and further study.

Alternative Remedies

Some women try nutritional supplements (such as soy products), botanicals (such as red clover), antioxidant vitamins (such as vitamin E), and herbal preparations (such as black cohosh, St. John’s wort, and Chinese herbal medicines). Most are safe for short-term use (up to six months), although if you are trying phytoestrogens they are probably more safely used when taken as food rather than as pills or supplements

Some of these remedies seem to help some women, but well-designed studies have often failed to show that they are beneficial. All studies of hot flashes using a placebo show a placebo effect (as many as 30 percent or more of women feel better even on inert tablets).

If you’re taking alternative remedies, tell your health care providers so they can stay alert to possible interactions with other medications.