Definition: Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin may redden, just as if you were blushing. Hot flashes can also cause profuse sweating and may leave you chilled.

Although other hormonal conditions can cause them, hot flashes most commonly are due to menopause — the time of life when a woman's menstrual periods stop.

Depending on the person, hot flashes may occur a few times a week or several times a day. Hot flashes that occur at night can interrupt your sleep. If your hot flashes become particularly bothersome, a variety of treatments are available.

Symptoms
When you're having a hot flash, you may experience:
A feeling of warmth spreading through your upper body and face

A flushed appearance with red, blotchy skin

Rapid heartbeat

Perspiration, mostly on your upper body

A chilled feeling as the hot flash subsides

Hot flashes vary in frequency — you may have many in one day or just a few each week. Each hot flash usually subsides in just a few minutes. Most women who experience hot flashes will have them for at least a year.
When to see a doctorIf hot flashes become particularly bothersome and disrupt your daily routines, consider making an appointment with your doctor to discuss treatment options.

Causes
The exact cause of hot flashes isn't known, but the signs and symptoms point to factors affecting the function of your body's thermostat — the hypothalamus. This area at the base of your brain regulates body temperature and other basic processes. The estrogen reduction you experience during menopause may disrupt hypothalamic function, leading to hot flashes.
Low estrogen alone doesn't often seem to induce hot flashes, as children and women with low levels of estrogen due to medical conditions usually don't experience hot flashes. Instead, the withdrawal of estrogen, which happens during menopause, appears to be the trigger.

Risk factors
Not all women who go through menopause experience hot flashes. Although it's not clear why some women get hot flashes and others don't, the following factors increase your risk of hot flashes:

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.

Physical inactivity. If you don't exercise, you're more likely to have hot flashes during menopause.

Ethnicity. More African-American women report menopausal hot flashes than do women of European descent. Hot flashes are less common in women of Japanese and Chinese descent than in white European women.

Complications
Sleep problems are often a complication of hot flashes. Nighttime hot flashes (night sweats) can wake you from sleep and, over time, may cause chronic insomnia. These sleep disturbances can, in turn, eventually lead to memory problems, anxiety and depression in some women.

Tests and diagnosis
Your doctor can usually diagnose hot flashes based on a description of the symptoms you're experiencing. To confirm the cause of your hot flashes, your doctor may suggest blood tests to check whether you are approaching menopause and if your thyroid gland is working properly. Hot flashes can also be caused by an overactive thyroid gland (hyperthyroidism).

Treatments and drugs
The most effective treatment for hot flashes is estrogen, but taking this hormone can increase your risk of developing other health problems in the future. Medications such as antidepressants and anti-seizure drugs also may help reduce hot flashes. Discuss the pros and cons of various treatment plans with your doctor. If hot flashes don't interfere with your life, you may need no treatment at all.

For most women, hot flashes fade gradually within a few years.

Hormone therapyEstrogen and progesterone are the hormones used to reduce hot flashes. Women who have had a hysterectomy can take estrogen alone. But if you still have a uterus, you should take progesterone along with estrogen to protect against cancer of the lining of the uterus (endometrial cancer). With either regimen, current recommendations are to use the lowest effective dose for the shortest amount of time needed to relieve symptoms.
Before starting estrogen therapy for menopause symptoms, review your heart-disease risk factors with your doctor, and weigh the benefits of symptom relief against the risk — remote but recognized — of developing heart disease as a result. Estrogen therapy is not a good option if you've ever had a blood clot or breast cancer.

As an alternative for women who can't take estrogen, some doctors prescribe progesterone alone to help control hot flashes.

AntidepressantsLow doses of certain antidepressants may decrease hot flashes. Examples include:
Venlafaxine (Effexor, Pristiq)
Paroxetine (Paxil, Pexeva)
Fluoxetine (Prozac, Sarafem)

However, these medications aren't as effective as hormone therapy for severe hot flashes and may cause side effects, such as nausea, dizziness, weight gain or sexual dysfunction. But they can be very helpful in women who cannot use estrogen or progesterone for relief of hot flashes.

Other prescription medications:

Gabapentin (Neurontin, Gralise). Gabapentin is an anti-seizure medication that's moderately effective in reducing hot flashes, particularly for women who have symptoms at night. Side effects can include drowsiness, dizziness and headaches.

Clonidine (Catapres, Jenloga, Kapvay, others). Clonidine, a pill or patch typically used to treat high blood pressure, may provide some relief from hot flashes. Side effects include dizziness, drowsiness, dry mouth and constipation.

Lifestyle and home remedies
If your hot flashes are mild, you may be able to manage them with lifestyle adjustment alone. Follow these tips:

Keep cool. Slight increases in your body's core temperature can trigger hot flashes. Dress in layers so that you can remove outer clothing when you feel too warm. Open a window or use a fan or air conditioner to keep air flowing. 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 own triggers and avoid foods or drinks that bring on hot flashes.

Relax. Some women find relief from mild hot flashes through yoga, meditation, relaxation or other stress-reducing techniques. Even if these approaches don't quell your hot flashes, they may provide other benefits, such as easing the sleep disturbances that tend to occur with menopause.

Don't smoke. Smoking is linked to increased hot flashes. By not smoking, you may reduce hot flashes, as well as your risk of many serious health conditions such as heart disease, stroke and cancer.

Alternative medicine
Many women have turned to a variety of dietary supplements to help curb hot flashes, sometimes with the mistaken belief that "natural" products can cause no harm. All supplements 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 used for menopause symptoms include:

Plant estrogens. Women in Asian countries, where soy is a regular part of the diet, 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 ingestion of estrogen-like compounds in soy, red clover and many other plants. However, studies giving soy to women with hot flashes have generally found no benefit.

Black cohosh. Black cohosh has been popular among many women with menopausal symptoms. But there's little evidence that black cohosh is effective, and the supplement can be harmful to the liver.

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.

Kava. Kava may ease anxiety, but not hot flashes. It also can damage the liver.

Resource: The Mayo Clinic