What are hot flashes, when do they occur, and how long do they last?

Vasomotor symptoms (VMS), more commonly known as hot flashes and night sweats, affect roughly 80% of women in their late-forties to mid-fifties. They often begin in perimenopause (i.e., the time around menopause), and peak in the later perimenopause and early postmenopausal years. Hot flashes present as a feeling of intense heat, resulting in sweating and flushing, predominantly around the head, neck, chest, and upper back. The physiology of hot flashes is not fully known, but they are presumed to be linked to low estrogen and elevated luteinizing hormone.^[1]

Not all menopausal women experience hot flashes, so there may be other biological mechanisms at play. Some evidence points to a narrowing of the thermal neutral zone (the range of body temperatures where an organism doesn’t have to expend extra energy to warm or cool) during menopause, meaning slight temperature fluctuations can trigger thermoregulatory processes that dissipate heat, resulting in flushing and sweating.^[2]