Winfrey, 71, said that in addition to a loss of concentration, she also suffered from heart palpitations -- a sensation of a racing or irregular heartbeat -- which she said she did not know were a symptom of menopause, the time in life when a woman's periods stop permanently.

Oprah Winfrey has opened up about her challenging menopause experience, including severe concentration issues that forced her to pause Oprah’s Book Club. Her story highlights lesser-known symptoms, such as heart palpitations,

Oprah Winfrey is back on Monday night and taking on a subject that impacts over half the population but doesn't nearly get enough attention: menopause.