Menopause is when a woman stops menstruating (having menstrual cycles). During menopause, women may begin to experience side effects related to the hormonal changes that take place at this time. Sleep disorders are among the most common symptoms reported by women during menopause.

Natural menopause, sometimes referred to as “the change” or “change of life,” occurs when the body no longer releases eggs every month, and the ovaries produce substantially less estrogen  and progesterone. Surgical removal of the ovaries (oophorectomy) will cause immediate menopause in a woman, regardless of age. Surgical menopause also causes more severe symptoms than natural menopause because the change in hormone levels is so abrupt.

A woman is considered to have entered menopause when she does not have a menstrual cycle (also known as a period) for 12 consecutive months. In most cases, this occurs when a woman is between 45 to 55 years old, although for various reasons it can happen earlier or later in life. The average age of menopause for women in the United States is 51, according to the National Institutes of Health.

Natural menopause is preceded by a period of transition known as perimenopause. This can begin as early as a woman’s 30s. Perimenopause may end after several months, or may unfold over many years.

Women experiencing menopause report more sleep problems than any other group of women, according to the National Sleep Foundation. In many cases, women begin complaining of sleep disturbances, such as insomnia, in the late 30s and early 40s without realizing that they may have entered perimenopause. For such women, this period of transition is the cause of sleeping problems.

Symptoms associated with menopause cause discomfort that can interfere with a woman’s ability to sleep soundly. Menopausal symptoms that may disrupt sleep include:

• Reduced hormone production. Throughout perimenopause and menopause, the ovaries produce reduced amounts of estrogen and progesterone. This latter hormone helps promote sleep. Thus, as progesterone levels drop, women may have more trouble sleeping.
  
  
• Hot flashes. Hormonal changes that occur during menopause affect the hypothalamus, the region of the brain that regulates body temperature and sleep. These hormonal changes can cause the body temperature to rise, which is usually felt first in the face and chest. These hot flashes may occur at any time of day or night. When they occur at night, they can disrupt sleep. Hot flashes tend to occur more frequently in the first part of the night and less frequently later in the night, when a person reaches REM stage sleep (when dreaming occurs). Menopausal women will often awaken just prior to the beginning of the hot flash, as the body temperature begins to rise. Most hot flashes last about three minutes. Hot flashes that occur at night are often called “night sweats” due to the excessive perspiration that commonly occurs along with the hot flash, further disrupting a woman’s sleep.
  
  
• Mood disorders. About 20 percent of women experience depression during menopause, according to the National Sleep Foundation. Depression can lead to sleep disruptions.

Women who experience sleeping difficulties during menopause are more likely to feel tired and to experience anxiety and depression. Headaches are also associated with inadequate sleep during menopause.