Your period turns up five days early, then a week late. You wake at 3am and lie there until the alarm. You snap over something small, then lose the name of a colleague you have known for years. Each of these is easy to blame on stress or a busy life. Put together, they are often the signs that perimenopause has started.
These are questions I hear all the time from my patients: is this just me, am I imagining it, should I be coping better? You are not imagining it. What you are noticing is usually a pattern, and once a pattern has a name, it can be understood and treated.
The signs that perimenopause has started are easy to explain away
Perimenopause is the phase leading up to menopause, when the ovaries produce hormones less predictably. Oestrogen and progesterone swing up and down rather than falling steadily, which is why symptoms tend to come and go in waves: a good fortnight, then a hard one.
Menopause itself is your final period, confirmed once 12 months have passed without another. In the UK, the average age of menopause is 51, and the early stage of the transition begins on average six to eight years before the final period. That is why so many women notice changes in their mid-forties. My article on what age perimenopause starts looks at timing in more detail.
Some women notice symptoms in their late thirties. If your periods stop before 40, this may be premature ovarian insufficiency, which always needs detailed medical assessment and usually treatment, rather than waiting to see.
No single symptom proves anything on its own. It is the combination that tells the story.
It usually shows up in your cycle, your sleep and your mood
For most women, the cycle is the first clue. Periods may arrive a week or more earlier or later than usual, become heavier or lighter, or occasionally be skipped. Premenstrual symptoms such as breast tenderness, bloating and irritability often become stronger. But you can also have normal periods and be in perimenopause.
Some bleeding should never be put down to hormones. Bleeding between periods, bleeding after sex, or any bleeding after 12 months without a period should always be checked by a doctor.
Sleep often starts to break, too. Hot flushes and night sweats can range from a brief warmth across the chest and face to drenching episodes that wake you repeatedly. Again some women never experience hot flushes and sweats, but they can still be in perimenopause. But sleep can become lighter and more broken even without them, with early waking and difficulty drifting off again. Poor sleep then makes almost everything else harder, from mood and concentration to energy and appetite (I know this can be hard!).
Mood and memory changes are among the most overlooked signs and the most common in perimenopause. Many women describe new or worsening anxiety, tearfulness, irritability, a loss of confidence, or low mood that feels different from ordinary stress. Brain fog is common too: losing words, forgetting names, rereading the same paragraph. Please don’t ignore your mood changes as they are part of the menopause picture, and for some women they are the main symptom.
Your skin, hair and shape can change as well. Oestrogen supports collagen, skin hydration and hair growth, so some women notice drier or itchier skin, thinning hair, adult acne or more facial hair. Weight often shifts towards the tummy even when diet and activity have not changed, and muscle can be lost more easily. These are physical changes, not a failure of willpower.
Some of the clues seem to have nothing to do with hormones
Some changes are so rarely linked to hormones that women can spend months seeing different specialists before anyone mentions perimenopause. None of these alone proves anything, but alongside cycle or sleep changes they are worth raising.
Aches and stiffness. Some women notice new joint or muscle aches, often worse first thing in the morning.
A racing or fluttering heart. Palpitations can happen during the transition, but they should always be checked by a doctor so that heart and thyroid causes can be ruled out first.
Headaches that change. Migraines may become more frequent or behave differently as hormones fluctuate.
Other surprises. Tinnitus, dizziness, dry eyes, or a tiredness that sleep does not seem to fix.
Vaginal and bladder changes. Dryness, discomfort during sex, needing to pass urine more often or urgently, and repeated urinary infections can begin in perimenopause, although they are more common later. Unlike hot flushes, these symptoms tend to persist or worsen without treatment, and they usually respond well to it. There is nothing to gain from putting up with them quietly.
You probably don't need a blood test, but you do need a conversation
Most of the answer comes from listening. I ask about your cycle, your symptoms and when they started, your contraception, your medical and family history, and how all of this is affecting daily life.
For women over 45, perimenopause can be diagnosed from vasomotor symptoms (hot flushes and night sweats) together with irregular periods, without a hormone test. Follicle-stimulating hormone (FSH) levels swing from week to week during this stage, so a normal result does not rule perimenopause out. NICE says an FSH test can be considered for women aged 40 to 45 with menopausal symptoms, including a change in their cycle, and for women under 40 where premature ovarian insufficiency is suspected. FSH is not a reliable guide if you are taking combined hormonal contraception or high-dose progestogen.
Other blood tests are often more useful, because an underactive or overactive thyroid, iron deficiency and anaemia can all mimic perimenopause. Depending on your symptoms, I may check thyroid function, a full blood count or ferritin. A new breast lump, unexplained weight loss, chest pain or persistent palpitations should always be checked promptly, rather than put down to hormones. If you are not sure which stage you are in, my guide on perimenopause or menopause and how to tell where you are may help.
The most useful thing you can do before an appointment is keep a simple diary for a couple of months. Small notes are enough: the day your period starts and how heavy it is, how many times you woke last night, one word for your mood, and any flushes. It takes seconds a day, and I promise they add up. Laid out side by side, a few weeks of notes usually show the pattern far more clearly than memory can.
There is more help than most women are offered
There is no single right approach. The best plan depends on your symptoms, your health history and what matters most to you.
Everyday foundations. UK physical activity guidelines recommend muscle-strengthening activity on at least two days a week, alongside regular aerobic exercise, which supports muscle and bone as oestrogen falls. Enough protein, calcium and vitamin D, a regular sleep routine and a cooler bedroom all help. Alcohol often makes flushes and sleep worse, so cutting back is worth trying. Stopping smoking matters too, as smoking is linked to an earlier menopause and higher cardiovascular risk.
Talking therapy. NICE recommends cognitive behavioural therapy (CBT) as an option for hot flushes and night sweats, sleep problems, and low mood related to the menopause.
HRT. I want us to move away from the idea that you have to wait for your periods to stop. HRT can be started during perimenopause, and NICE and the British Menopause Society regard it as the most effective treatment for hot flushes and night sweats. It can also help with sleep, mood and vaginal symptoms, and it helps protect bone health. Oestrogen can be taken as a tablet or through the skin as a patch, gel or spray. If you still have a womb, you also need a progestogen to protect the womb lining.
An honest look at the risks. Combined HRT is linked to a small increase in breast cancer risk, which relates to how long it is taken. Oestrogen tablets raise the risk of blood clots, but patches, gels and sprays do not appear to at standard doses. HRT is not suitable for everyone, and some women who have had certain cancers or blood clots will need a different plan. If you have a history of breast cancer, blood clots, migraine with aura or heart disease, a detailed and personal discussion is especially important before choosing any treatment.
Local treatment. Vaginal oestrogen treats dryness and bladder symptoms directly, at a very low dose, and can be used alongside HRT or on its own.
If hormones are not right for you. You still have options. In 2026, NICE recommended fezolinetant for moderate to severe hot flushes and night sweats when HRT is unsuitable. It needs liver blood tests before starting and monthly for the first three months, and you should seek advice promptly if you notice symptoms such as yellowing skin, dark urine or itching. Certain antidepressants, gabapentin and clonidine may also be considered.
Contraception still matters. You can still become pregnant during perimenopause, and HRT is not a contraceptive. If you are not using hormonal contraception, you should continue contraception for two years after your last period if you are under 50, or one year if you are over 50. All women can stop at 55. A hormonal coil (the 52 mg levonorgestrel IUS) can provide both contraception and the womb protection needed with HRT.
Perimenopause is also a good moment to review blood pressure, cholesterol and bone health for the years ahead.
It is the pattern that matters, and you do not have to wait it out
It is worth seeing a doctor if your symptoms are affecting your work, relationships, sleep or mood, if your periods change before the age of 45, or if earlier advice has not helped. Please do not wait if you have bleeding between periods, bleeding after sex, very heavy bleeding, or any bleeding after 12 months without a period.
A late period, a 3am wake-up and a lost word are easy to dismiss one at a time. Together, they are a pattern, and a pattern can be assessed, explained and treated, whether that means HRT, a non-hormonal option or a plan built around what is safe for you. Waiting to see if it passes is not a plan. You deserve an answer now. You can read more about my menopause and hormonal wellness service.
In one unhurried 45-minute consultation at 10 Harley Street, Dr Katy Kasraie will look at your health history, your goals and every suitable option, including approaches that do not involve medication. No referral needed, and most major insurers are accepted. Click here to book your appointment.