The hot flushes are very common in perimenopause, but not all women experience them, and not all flushes are of the same intensity. Hot flushes can be as mild as a light blush or severe enough to wake you from a sound sleep and be associated with perspiration (called night sweats). It lasts for 30 seconds to 5 minutes. They usually disappear within a few years after menopause, but in some women they can continue for decades.