Symptoms of low oestrogen: the signs, the causes and what to do

Oestrogen is not a reproductive hormone that happens to have side effects elsewhere. There are oestrogen receptors in the brain, bones, blood vessels, skin, bladder, joints and gut, which is why falling levels produce such a scattered list of symptoms, and why so many women spend years being treated for each one separately.

This article sets out the symptoms, what causes low oestrogen at different ages, how it is diagnosed in the UK, and what the treatment options are.

The symptoms

Most women do not get all of these. Most get several, and the combination matters more than any single one.

Temperature. Hot flushes and night sweats are the classic signs, because oestrogen helps set the brain’s thermostat. Around three quarters of women get them at some point.

Sleep. Waking in the early hours and being unable to get back off, with or without sweats. Sleep problems are frequently the first thing women notice, years before flushes.

Mood and mind. Anxiety that arrives from nowhere, low mood, irritability, loss of confidence and brain fog: losing words, losing the thread, walking into rooms and forgetting why.

Vaginal and urinary. Vaginal dryness, discomfort during sex, needing to pass urine more urgently or more often, and repeated urinary infections. Unlike flushes, these tend to get worse over time without treatment.

Body. Joint pain and stiffness, particularly in the morning. Headaches or a change in migraine pattern. Palpitations. Dry, itchy or thinning skin. Hair thinning. Weight settling around the middle even when nothing else has changed. Fatigue that sleep does not fix.

Desire. Low libido, partly from the direct effect of low oestrogen and partly from everything above.

Periods. If you are still having them, cycles that shorten, lengthen, get heavier or become unpredictable.

Then there are the changes you cannot feel. Bone density falls fastest in the first few years after oestrogen drops, and the protective effect of oestrogen on blood vessels is lost. Neither produces symptoms until something breaks.

Why oestrogen falls

Perimenopause. For most women this begins in the 40s. Oestrogen does not simply fall; it swings, sometimes higher than before and sometimes much lower, and the swings are what make symptoms so variable from week to week. Our perimenopause guide covers this stage in detail, including why blood tests are often unhelpful during it.

Menopause. The point at which periods have stopped for a year. The average age in the UK is 51. Oestrogen settles at a low level and stays there.

Premature ovarian insufficiency. Ovaries stopping before 40, which affects around one in a hundred women. This needs proper investigation and specialist care, because of what it means for bones, heart and fertility, and HRT is usually recommended until at least the average age of menopause.

Surgical and medical menopause. Removal of the ovaries causes an abrupt drop with often severe symptoms. Chemotherapy, radiotherapy to the pelvis, and medicines that suppress oestrogen (used for endometriosis, fibroids and some breast cancers) do the same.

Other causes. Very low body weight, heavy exercise and sustained stress can switch off the signals from the brain that drive the ovaries. Breastfeeding lowers oestrogen temporarily. Rarely, a problem with the pituitary gland, such as a raised prolactin, is responsible.

How it is diagnosed

This depends almost entirely on your age.

• Over 45 with typical symptoms: NICE guidance says menopause and perimenopause can be diagnosed from symptoms alone, without a blood test. Hormone levels fluctuate so much that a single reading is often more misleading than useful.
• Between 40 and 45: a blood test measuring FSH, the hormone the brain uses to drive the ovaries, can support the diagnosis alongside your symptoms.
• Under 40: FSH should be checked twice, four to six weeks apart, and raised results need referral rather than a prescription.

Whatever your age, thyroid problems, low iron and low vitamin B12 produce a very similar picture and are worth ruling out. Our page on whether you need a blood test explains when testing helps and when it does not, and our blood tests cover the female hormones alongside thyroid and the common look-alikes.

What treats it

HRT replaces the oestrogen, usually as a patch or gel, with a progestogen to protect the womb lining if you have a womb. It is the most effective treatment for the great majority of the symptoms above, and for most women under 60 or within ten years of menopause the benefits outweigh the risks. Our guide to HRT in the UK goes through the types, the risks and how to get it.

Vaginal oestrogen treats the vaginal and urinary symptoms directly, with very little absorbed into the rest of the body. It can be used on its own, alongside HRT, and long term.

Testosterone is sometimes added where desire stays low on established HRT. Levels of testosterone fall alongside oestrogen and are routinely overlooked.

Non-hormonal options exist for women who cannot or would rather not take HRT, and lifestyle changes help many symptoms at the margins and protect bones and heart regardless.

The common failure is treating the symptoms one at a time: an antidepressant for the mood, a sleeping tablet for the nights, physiotherapy for the joints, antibiotics for the urinary infections. When the cause is low oestrogen, treating that, with a plan built around your particular set of symptoms, is usually simpler and works better.

When to see a doctor promptly

Most of this can wait for a planned appointment. Some things should not:

• Any bleeding after the menopause, or bleeding between periods or after sex
• Night sweats with weight loss, fever or swollen glands
• Palpitations with chest pain, breathlessness or fainting
• Periods stopping before 40

The bottom line

Low oestrogen produces symptoms all over the body because oestrogen works all over the body. If several of the signs above have arrived together in your 40s or 50s, they are more likely to be one problem than six, and it is a problem with good treatment. A doctor who takes the whole list seriously is the starting point.