Tiredness in perimenopause: common causes and everyday habits that help

Strictly speaking, this stage is known as perimenopause or the menopausal transition. Tiredness can result from a combination of factors and is not solely due to hormonal decline:

• Fluctuations in oestrogen and progesterone can affect sleep, mood and perceived energy levels.
• Hot flushes and waking during the night can disrupt sleep, even if you do not always remember these episodes the following day. Studies show that vasomotor symptoms tend to occur alongside insomnia and fatigue. Harlow et al., 2017.
• Heavy or prolonged periods can reduce iron stores. A longitudinal study involving 2,329 women linked heavy bleeding during the menopausal transition with a greater likelihood of feeling tired. However, ferritin levels were not measured and, therefore, the study did not demonstrate that iron was the underlying mechanism. Harlow et al., 2025.
• Stress, anxiety or low mood can worsen both sleep and fatigue.
• An underactive thyroid, sleep apnoea, diabetes, certain medicines and other health conditions can cause similar symptoms.

For this reason, persistent tiredness should not automatically be assumed to be ‘just hormonal’. It is advisable to consult a healthcare professional so that each case can be assessed individually.

It is advisable to seek medical assessment if the tiredness:

• Persists for several weeks or gradually becomes worse.
• Interferes with work, physical activity or everyday tasks.
• Does not improve after sleep or rest.
• Occurs alongside very heavy or prolonged periods.
• Is accompanied by paleness, shortness of breath, palpitations, sensitivity to cold, constipation or a noticeable loss of strength.
• Occurs alongside persistent low mood, loss of interest or severe anxiety.
• Is associated with loud snoring, pauses in breathing or daytime sleepiness.
• Begins after starting a medicine or supplement.

Normal tiredness is usually related to exertion or a night of insufficient sleep and improves with rest. Clinically relevant fatigue may present as:

• Exhaustion that is disproportionate to the level of activity performed.
• Waking up feeling unrefreshed.
• Difficulty concentrating or ‘brain fog’.
• Reduced exercise tolerance.
• Loss of motivation or a need to cut back on usual activities.

There is no test that can identify a specific form of ‘hormonal tiredness’. The overall pattern, accompanying symptoms and test results can help determine whether insomnia, hot flushes, iron deficiency, a thyroid disorder or another cause is more likely to be contributing.

The best approach is to consult a healthcare professional and explain all your symptoms so that they can request any investigations and tests they consider appropriate. These may include, among others:

• Full blood count.
• Ferritin.
• Vitamin B12.
• Folate.
• Vitamin D.

There is no specific or established average duration. Perimenopause usually lasts for two to four years, although it may be shorter or longer depending on the individual. Tiredness may fluctuate with the menstrual cycle, bleeding, sleep and hot flushes.

Severe fatigue should not be assumed to be something that simply has to be endured until menopause. If it is related to iron deficiency, an underactive thyroid, sleep apnoea, low mood or severely disrupted sleep, it may improve once the underlying cause has been addressed. For this reason, it is advisable to consult an appropriately qualified healthcare professional.

Follow the directions for use and any warnings on the label, and do not exceed the recommended daily intake. If you are taking medication, speak to a healthcare professional before starting any food supplement.

Fatigue may improve. Once periods stop, menstrual iron losses also cease and, over time, some women experience fewer hormonal fluctuations, less bleeding and fewer sleep disturbances.