If your periods have started to change in your 40s, or you keep waking up hot at night, perimenopause is one likely explanation. Noting your cycle dates, how heavy each period is and any other symptoms for a few months makes a pattern easier to spot and gives you something concrete to show a doctor.
What is perimenopause?
Perimenopause is the run-up to menopause, a stretch of time when hormone levels change and periods start to shift. The NHS sums it up this way: "Perimenopause happens when your periods become irregular and menopause is when your periods stop altogether." Menopause itself is a single point, defined as 12 months without a period when you are not using hormonal contraception. The years after that point are called postmenopause.
When does perimenopause start, and how long does it last?
For most people it begins in their 40s. The US Office on Women's Health says perimenopause "usually begins in your mid- to late 40s", although some women notice symptoms in their mid- to late 30s. It lasts about four years on average and can run for up to 10 years. MedlinePlus, from the US National Library of Medicine, gives 45–55 as the most common age range for reaching menopause.
Symptoms do not always stop when periods do. The NHS symptoms guide says they "usually last for 7 to 9 years, sometimes longer", and that they can change along the way: hot flushes may ease, for example, while low mood or anxiety become more noticeable. Menopause before 45 is called early menopause, and before 40 it is called premature menopause, according to the NHS page on early menopause.
What are the early signs of perimenopause?
According to the NHS, "One of the first signs of perimenopause is usually a change to your periods." Other symptoms often appear alongside or soon after. The Office on Women's Health notes that symptoms "can be mild, moderate, or severe", and not everyone has all of them.
| Symptom | What you might notice |
|---|---|
| Changes to periods | Periods come more or less often, bleeding gets heavier or lighter, or a period is skipped |
| Hot flushes | Sudden heat in the face, neck and chest, sometimes with sweating, a racing heart or dizziness, that can last several minutes |
| Night sweats | Hot flushes during the night, with sweating that can disturb sleep |
| Sleep problems | Trouble getting to sleep or staying asleep, often worse with night sweats |
| Mood changes | Mood swings, irritability, anxiety or low mood |
| Brain fog | Problems with memory or concentration, often worse when you are tired |
| Vaginal dryness | Dryness, burning, itching or irritation, and sex that may feel uncomfortable or painful |
| Bladder changes | More frequent urine infections, or symptoms that feel like one, and leaking urine |
| Aches | Joint and muscle pain or stiffness |
| Other changes | Palpitations, worse headaches or migraines, lower sex drive, dry or itchy skin, thinning hair, and weight gain around the middle |
Brain fog in particular tends to worry people, but the Office on Women's Health says these memory and thinking changes "are common in perimenopause and often improve after menopause." Aches are common too: the same office reports that in a review of 37 studies, 57% of women in perimenopause had muscle or joint pain, compared with 40% of women before perimenopause.
How is perimenopause different from menopause?
| Perimenopause | Menopause and after | |
|---|---|---|
| What it is | The transition years while hormone levels change | Menopause is the point 12 months after your last period; postmenopause is the time after it |
| Periods | Still happen, but often irregular | Stopped |
| Pregnancy | Still possible, even if you skip periods | No longer possible |
| Bleeding | Changes in pattern are common, though some need checking | Any vaginal bleeding should be checked by a doctor |
| Symptoms | Often begin here | Can carry on; vaginal dryness and joint pain may persist |
The Office on Women's Health is clear that "You can get pregnant during perimenopause, even if you skip periods", so it is worth talking to a doctor or nurse about contraception if you do not want to become pregnant.
How do doctors confirm perimenopause?
Usually without a single test. The NHS says "There's no routine test for perimenopause and menopause" and that a doctor may diagnose it from your age and symptoms. If you are under 45 and have menopause symptoms, a GP may sometimes do blood tests. Your symptom notes help here.
What lifestyle steps can help with perimenopause symptoms?
Some everyday changes target particular symptoms, and others mainly protect long-term health. The evidence behind them varies, as the table shows.
| Step | What it may help | What the evidence says |
|---|---|---|
| Keep cool: light layers, a fan, a cool bedroom, a cool shower or a cold drink | Hot flushes and night sweats | Practical comfort measures suggested in the NHS self-help advice |
| Notice your triggers, such as spicy food, caffeine, hot drinks and alcohol | Hot flushes | Listed as possible triggers by the NHS and MedlinePlus; a symptom diary shows which ones matter for you |
| Regular exercise, including strength and weight-bearing activity | Mood and bone strength | Recommended by the NHS. A Cochrane review found the evidence "insufficient to show whether exercise is an effective treatment" for hot flushes and night sweats, so treat it as a whole-body habit rather than a hot flush fix |
| A regular sleep routine | Sleep, and the irritability and poor concentration that follow bad nights | Part of the NHS self-help advice |
| Not smoking, and keeping alcohol within recommended limits | Symptoms overall | The NHS says smoking "can make menopause symptoms worse" and that alcohol may affect symptoms |
| Cognitive behavioural therapy (CBT) | Low mood, anxiety, hot flushes and sleep | The NHS says CBT can help with low mood and anxiety, can help manage hot flushes and may help with sleep problems |
| Calcium-rich foods and some daylight for vitamin D | Bone health | Part of the NHS advice for protecting bones around menopause |
Check with a doctor or pharmacist before trying herbal or complementary remedies, as both the NHS and MedlinePlus advise. If you plan to build up your activity, how much exercise you actually need sets out a realistic weekly target.
Are there treatments for perimenopause symptoms?
Yes. When symptoms get in the way of daily life, a doctor can go through the options, which include hormone therapy as well as talking therapies such as CBT. MedlinePlus explains that a health care provider will talk through "your symptoms, family and medical history, and preferences" and can "explain the risks and benefits of the treatments." That conversation belongs with a doctor, so this article does not recommend any particular treatment.
When should you see a doctor about perimenopause symptoms?
Changes to your periods are expected in perimenopause, but some bleeding patterns need checking because they can have other causes. See a GP or doctor if:
- Your bleeding is heavier than before. The NHS flags a pattern where "you're bleeding more, not less, than before". Its heavy periods page describes heavy bleeding as needing to change a pad or tampon every 1–2 hours, periods lasting more than 7 days, passing clots larger than about 2.5cm, or bleeding through to clothes or bedding.
- You bleed between periods or after sex. The NHS lists both as reasons to see a GP.
- You have any bleeding after 12 months without a period, even a single episode or light spotting. The NHS says this is not usually serious, but it should always be checked.
- You have palpitations, a fast or pounding heartbeat.
- Symptoms are affecting your daily life, your work, sleep or relationships. The NHS notes that "Early advice can help reduce the effects of menopause and perimenopause on your health, relationships and work."
- You are under 45 and have symptoms that sound like perimenopause, since early menopause has its own causes and checks.
If low mood will not lift, or you have thoughts of harming yourself, seek help urgently rather than waiting for a routine appointment. Feeling tired or short of breath a lot alongside heavy periods is also worth raising, and when tiredness is worth seeing a doctor about covers other causes of ongoing fatigue.
Perimenopause is a natural part of life, but troublesome symptoms are still worth acting on. If night sweats are breaking up your sleep, the ideal bedroom temperature for sleep and the sleep hygiene checklist cover the practical side. For cycles, hormones and health through every life stage, see the full guide to women's health.
