A hot flash is a sudden sensation of intense body heat, often with profuse sweating and reddening of the head, neck, and chest. These symptoms can be accompanied by mild to severe heart palpitations, anxiety, irritability and, in rare cases, panic.

Hot flashes are the most common symptom of a woman's changing estrogen levels around the time of menopause. They strike unexpectedly, often at night, and usually last several seconds to minutes. Hot flashes:

• Affect some women during perimenopause, when estrogen levels are changing.
• Most commonly affect women during the first 1 to 2 years after menopause, when estrogen levels have dropped below a certain point. Women who become menopausal from chemotherapy, from surgical removal of the ovaries (oophorectomy) during hysterectomy, or from antiestrogen treatment for breast cancer are especially likely to have severe hot flashes.
• Continue to affect some women for 5 years or more after menopause.
• Can happen normally during stress or embarrassment for women of all ages.

Hot flashes are less commonly caused by thyroid problems, cancers, and psychological stress. Men commonly have hot flashes when taking hormone therapy for prostate cancer.

Several medicines are available to treat hot flashes.