What are the symptoms of low estrogen?

The symptoms of low estrogen include hot flushes, night sweats, vaginal dryness, mood changes, poor sleep, brain fog, and joint aches — the same cluster that defines perimenopause and menopause, because that's the most common cause.

Oestrogen affects the brain, bones, skin, heart, and reproductive tissues, so low levels show up widely: hot flushes and night sweats; vaginal dryness, discomfort, and urinary symptoms; mood swings, anxiety, or low mood; disrupted sleep; brain fog; thinning hair and dry skin; reduced libido; and joint or muscle aches. Over the longer term, low oestrogen also accelerates bone loss. While menopause is the usual reason, low oestrogen can also come from other causes — certain medical treatments, very low body fat or over-exercising, or premature ovarian insufficiency in younger women.

If you're young (under 40) with these symptoms and irregular or absent periods, it's especially worth investigating, since early low oestrogen needs proper assessment.

What to do: if these symptoms fit and you're around the typical age, perimenopause or menopause is the likely cause — and treatment (including HRT) can restore much of what's lost. If you're younger, or symptoms are severe, see your GP for assessment, since the cause and management differ. Either way, you don't have to simply live with significant symptoms.