A hot flash is the sudden feeling of warmth in the upper body, which is usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. A hot flash can also cause sweating. If you lose too much body heat, you might feel chilled afterward. Night sweats are hot flashes that happen at night, and they may disrupt your sleep.

Although other medical conditions can cause them, hot flashes most commonly are due to menopause — the time when menstrual periods become irregular and eventually stop. In fact, hot flashes are the most common symptom of the menopausal transition.

There are a variety of treatments for bothersome hot flashes.

During a hot flash, you might have:

• A sudden feeling of warmth spreading through your chest, neck and face
• A flushed appearance with red, blotchy skin
• Rapid heartbeat
• Perspiration, mostly on your upper body
• A chilled feeling as the hot flash lets up
• Feelings of anxiety

The frequency and intensity of hot flashes vary among women. A single episode may last a minute or two — or as long as 5 minutes.

Hot flashes may be mild or so intense that they disrupt daily activities. They can happen at any time of day or night. Nighttime hot flashes (night sweats) may wake you from sleep and can cause long-term sleep disruptions.

How often hot flashes occur varies among women, but most women who report having hot flashes experience them daily. On average, hot flash symptoms persist for more than seven years. Some women have them for more than 10 years.

When to see a doctor

If hot flashes affect your daily activities or nighttime sleep, consider seeing your doctor to discuss treatment options.

Hot flashes are most commonly caused by changing hormone levels before, during and after menopause. It's not clear exactly how hormonal changes cause hot flashes. But most research suggests that hot flashes occur when decreased estrogen levels cause your body's thermostat (hypothalamus) to become more sensitive to slight changes in body temperature. When the hypothalamus thinks your body is too warm, it starts a chain of events — a hot flash — to cool you down.

Rarely, hot flashes and nights sweats are caused by something other than menopause. Other potential causes include medication side effects, problems with your thyroid, certain cancers and side effects of cancer treatment.

Not all women who go through menopause have hot flashes, and it's not clear why some women do have them. Factors that may increase your risk include:

• Smoking. Women who smoke are more likely to get hot flashes.
• Obesity. A high body mass index (BMI) is associated with a higher frequency of hot flashes.
• Race. More black women report having hot flashes during menopause than do women of other races. Hot flashes are reported least frequently in Asian women.

Hot flashes may impact your daily activities and quality of life. Nighttime hot flashes (night sweats) can wake you from sleep and, over time, can cause long-term sleep disruptions.

Research suggests that women who have hot flashes may have an increased risk of heart disease and greater bone loss than women who do not have hot flashes.

Your doctor can usually diagnose hot flashes based on a description of your symptoms. Your doctor might suggest blood tests to check whether you're in menopausal transition.

The most effective way to relieve the discomfort of hot flashes is to take estrogen, but taking this hormone carries risks. If estrogen is appropriate for you and you start it within 10 years of your last menstrual period or before age 60, the benefits can be greater than the risks.

Medications such as antidepressants and anti-seizure drugs also might help reduce hot flashes, although they're less effective than hormones.

Discuss the pros and cons of various treatments with your doctor. If hot flashes don't interfere with your life, you probably don't need treatment. Hot flashes subside gradually for most women, even without treatment, but it can take several years for them to stop.

Hormone therapy

Estrogen is the primary hormone used to reduce hot flashes. Most women who have had a hysterectomy can take estrogen alone. But if you still have a uterus, you should take progesterone with estrogen to protect against cancer of the lining of the uterus (endometrial cancer).

With either regimen, the therapy needs to be tailored to your needs. Guidelines suggest using the smallest effective dose for symptom control. How long you use the treatment depends on the balance of your risks and benefits from hormone therapy. The goal is to optimize your quality of life.

Some women who take progesterone with estrogen therapy experience progesterone-related side effects. For women who can't tolerate oral progesterone, a combination drug of bazedoxifene with conjugated estrogens (Duavee) is also approved for treating menopausal symptoms. Like progesterone, taking bazedoxifene with estrogen may help you avoid the increased risk of endometrial cancer from estrogen alone. Bazedoxifene might also protect your bones.

If you have had or are at risk of breast or endometrial cancer, heart disease, stroke or blood clots, talk to your doctor about whether estrogen therapy is right for you.

Antidepressants

A low-dose form of paroxetine (Brisdelle) is the only nonhormone treatment for hot flashes approved by the U.S. Food and Drug Administration. Other antidepressants that have been used to treat hot flashes include:

• Venlafaxine (Effexor XR)
• Paroxetine (Paxil, Pexeva)
• Citalopram (Celexa)
• Escitalopram (Lexapro)

These medications aren't as effective as hormone therapy for severe hot flashes, but they can be helpful to women who can't use hormones. Possible side effects include nausea, difficulty sleeping or drowsiness, weight gain, dry mouth or sexual dysfunction.

Other prescription medications

Other medications that might offer relief for some women include:

• Gabapentin (Neurontin, Gralise, others). Gabapentin is an anti-seizure medication that's moderately effective in reducing hot flashes. Side effects can include drowsiness, dizziness, water retention in the limbs (edema) and fatigue.
• Pregabalin (Lyrica). Pregabalin is another anti-seizure medication that can be effective in reducing hot flashes. Side effects can include dizziness, drowsiness, difficulty concentrating and weight gain.
• Oxybutynin (Ditropan XL, Oxytrol). Oxybutynin is a pill or patch most often used to treat urinary conditions like overactive bladder. It may also help relieve hot flashes in some women. Side effects can include dry mouth, dry eyes, constipation, nausea and dizziness.
• Clonidine (Catapres, Kapvay, others). Clonidine, a pill or patch typically used to treat high blood pressure, might provide some relief from hot flashes. Side effects include dizziness, drowsiness, dry mouth and constipation.

Nerve block procedure

A procedure known as stellate ganglian block has shown promise for treating moderate to severe hot flashes, but more research is needed. It involves injecting an anesthetic into a nerve cluster in the neck. The treatment has been used for pain management. Side effects include pain and bruising at the injection site.

If your hot flashes are mild, try managing them with these lifestyle changes:

• Keep cool. Slight increases in your body's core temperature can trigger hot flashes. Dress in layers so that you can remove clothing when you feel warm.

  Open windows or use a fan or air conditioner. Lower the room temperature, if you can. If you feel a hot flash coming on, sip a cold drink.

• Watch what you eat and drink. Hot and spicy foods, caffeinated beverages and alcohol can trigger hot flashes. Learn to recognize your triggers and avoid them.
• Practice mind-body therapies. Although evidence is inconclusive, some women find relief from mild hot flashes through mind-body therapies. Examples include meditation; slow, deep breathing; stress management techniques; and guided imagery. Even if these approaches don't help your hot flashes, they might provide other benefits, such as easing sleep disturbances that tend to occur with menopause.
• Don't smoke. Smoking is linked to increased hot flashes. By not smoking, you might reduce hot flashes, as well as your risk of many serious health conditions, such as heart disease, stroke and cancer.
• Lose weight. If you're overweight or obese, losing weight might help ease your hot flashes.

Many women have turned to alternative medicine, including mind and body techniques and dietary supplements to help curb hot flashes. There's a shortage of well-designed studies on complementary health practices for hot flashes, but research is progressing.

Mind and body approaches

A growing body of evidence suggests that certain techniques can help ease hot flashes, including:

• Cognitive behavioral therapy (CBT). CBT is a widely used type of individual or group counseling and is recommended by the North American Menopause Society as an effective treatment for hot flashes and night sweats. CBT doesn't typically reduce the frequency of hot flashes, but may reduce how much they bother you.
• Hypnosis. The North American Menopause Society recommends hypnosis for the treatment of hot flashes. Research indicates that hypnosis might help reduce both the frequency and severity of hot flashes.
• Mindfulness meditation. This type of meditation has you focus on what's happening from moment to moment. Although not shown to relieve hot flashes, it might reduce how much they bother you.
• Acupuncture. Some studies indicate that acupuncture might reduce the frequency and severity of hot flashes, but results are conflicting, with many studies showing improvements in both active and control groups, but no difference between the two groups.

Dietary supplements

People often assume that "natural" products cause no harm. However, all supplements may have potentially harmful side effects, and supplements can also interact with medications you're taking for other medical conditions. Always review what you're taking with your doctor.

Dietary supplements commonly considered for menopause symptoms include:

• Plant estrogens. Asian women, who consume soy regularly, are less likely to report hot flashes and other menopausal symptoms than are women in other parts of the world. One reason might be related to the estrogen-like compounds in soy.

  However, studies have generally found little or no benefit with plant estrogens, although research is ongoing to determine whether specific components of soy, such as genistein, help hot flashes.

• Black cohosh. Black cohosh has been popular among many women with menopausal symptoms. Studies of black cohosh's effectiveness have had mixed results, and the supplement might be harmful to the liver in rare circumstances.
• Ginseng. While ginseng may help with mood symptoms and insomnia, it doesn't appear to reduce hot flashes.
• Dong quai. Study results indicate that dong quai isn't effective for hot flashes. The supplement can increase the effectiveness of blood-thinning medications, which can cause bleeding problems.
• Vitamin E. Taking a vitamin E supplement might offer some relief from mild hot flashes. In high doses, it can increase your risk of bleeding.

For hot flashes, you'll likely start by seeing your family doctor or gynecologist.

What you can do

Before your appointment, make a list of:

• Your symptoms, including how many hot flashes you have a day and how severe they are
• Medications, herbs, vitamins and supplements you take, including doses
• Questions to ask your doctor

Take a family member or friend with you, if possible, to help you remember the information you get. Bring along a notepad or device to jot down information you receive.

Some basic questions to ask your doctor include:

• Do I need any tests?
• What treatments are available to help with my symptoms?
• What else can I do to relieve my symptoms?
• Are there alternative therapies I can try?
• Do you have printed information I can have? What websites do you recommend?

If other questions occur to you during the appointment, don't hesitate to ask them.

What to expect from your doctor

Some questions your doctor might ask include:

• Are you still having periods?
• When was your last period?
• How often do your symptoms bother you?
• How uncomfortable do your symptoms make you?
• Does anything seem to help?
• Does anything make your symptoms worse?