Perimenopause: What's Really Happening in Your Body?

Perimenopause isn’t just about your menstrual cycle. These changes can gradually affect your sleep, energy levels, mood, body composition, recovery, and overall well-being—often before you even realize that hormones might be playing a role.

Many women reach this stage of life without anyone having really explained to them what perimenopause means. As the body begins to change, it may seem as though several completely unrelated things are happening at once.

In fact, these changes may be part of the same transition period.

What is perimenopause?

Perimenopause is the period leading up to menopause, during which hormone levels in the ovaries begin to change.

Menopause itself refers to the point at which a woman has not had a menstrual period for 12 consecutive months. Perimenopause, however, can begin years before that.

The National Institute on Aging describes this as the transition leading up to menopause, during which menstrual cycles may change and hot flashes and other symptoms may occur. The NHS also emphasizes that the experience is highly individual—some women have few symptoms, while for others, they can significantly impact daily life.

Hormone levels do not change in a linear fashion

Estrogen affects much more than just the menstrual cycle. Among other things, it plays a role in sleep, brain function, bone health, skin, and body fat distribution. Progesterone is associated with the second half of the cycle, and changes in its levels can affect sleep and mood, for example. During perimenopause, these hormones do not change steadily but may fluctuate, which is why symptoms can vary widely.

Hormone levels can fluctuate, which is why symptoms may come and go. At one time, you may feel completely normal, while at another, changes affecting your sleep, mood, or energy levels may be much more noticeable.

What might you notice?

One of the first signs is often a change in the menstrual cycle. Periods may occur more frequently or less frequently, and the bleeding may be heavier or lighter than before.

However, the changes are not limited to the menstrual cycle. The NHS lists the following, among other things, as possible symptoms:

sleep problems, hot flashes, night sweats, mood swings, anxiety, difficulty concentrating, changes in libido, joint and muscle pain, and changes in the skin and hair.

That is precisely why the early stages of perimenopause can be so difficult to recognize. Many symptoms may simply seem like the result of stress, fatigue, or a hectic lifestyle.

Why might body composition change?

Many women notice that recovery takes longer, stress affects them more intensely, or their previous exercise and nutrition routines no longer yield quite the same results. This doesn’t mean you’re doing anything wrong. Your body’s needs may simply be changing.

It’s not just one hormone that’s responsible for this. Body composition is influenced by age-related changes in muscle mass, energy expenditure, sleep, stress, and daily activity, and hormonal changes may also play a role.

That’s why it’s worth thinking about more than just the number on the scale. Maintaining muscle mass, strength, sleep, and overall physical activity becomes increasingly important at this stage of life.

What can you do on your own?

Not all hormonal changes can be controlled, but daily habits make a difference.

The NHS recommends regular exercise, a balanced diet, adequate sleep, and weight-bearing and strength-building exercises during perimenopause and menopause. It’s also worth noting the effects of alcohol, caffeine, and stress on how you feel.

The goal isn't to do everything perfectly. It's much more important to develop habits that you can actually stick to consistently.

When Should You Ask for Help?

If these changes are affecting your sleep, mood, work, relationships, or overall quality of life, it's a good idea to talk to your doctor or gynecologist.

You don’t have to just put up with the symptoms of perimenopause. There are both hormonal and non-hormonal treatment options available, and the right solution depends on your symptoms, your overall health, and your personal preferences. The NHS considers HRT to be one of the main options for relieving perimenopausal and menopausal symptoms.

It’s better to talk about perimenopause sooner rather than later

The better you understand what's going on in your body, the easier it is to distinguish between normal changes and those that warrant seeking help.

This isn't a time when you should be fighting your body. Rather, it's a good time to reevaluate your habits and think about what your body really needs at this stage of life.