What perimenopause is and how to recognise it

Your sleep has got worse, your periods are less predictable, your mood swings, and yet your tests come back "normal". Sound familiar? Very often the reason is perimenopause — the transition years before your last period. It is not an illness but a stage every woman goes through. Yet it is rarely talked about, so many women spend years not understanding what is happening to them.

What is happening in the body

During the transition, hormones do not change smoothly or all at once.

Progesterone falls first, and steadily. After 40, more and more cycles happen without ovulation — and this is a normal part of the transition. Progesterone feeds the brain's natural "calming system", so its decline is most often felt as trouble falling asleep.

Oestrogen, meanwhile, does not fall — it swings. It drops, then spikes higher than usual, and only later goes down for good. What unsettles how you feel in these years is mainly the size of these swings, not the level itself. That is why it can feel like "nothing makes sense": one week is good, the next is hard.

How to recognise it

Perimenopause is recognised by a picture that builds up over time, not by a single test. Typical signs:

• Your cycle changes. Between 35 and 50, periods often become heavier, longer or more irregular.
• Sleep. It is harder to fall asleep, you wake more at night, your mind "won't switch off".
• Mood. Ups and downs, irritability, the days before your period feel stronger than they used to.
• Breasts and fluid. Fullness and tenderness in the breasts, bloating.
• Head. Migraines, "brain fog", poorer concentration.
• Hot flashes and night sweats. These can already start in these years.

You do not need to have all of them at once. The pattern matters more: what repeats and how it relates to your cycle.

What to do first

Start keeping track. The first day of your period, sleep, hot flashes, mood — every day, briefly. After a few weeks you will see connections that memory cannot hold. This is the best "test" of the transition.

Set a sleep anchor. Get up at the same time all seven days of the week, weekends included, and get 10–15 minutes of daylight in the first hour after waking. This is the strongest behavioural lever for sleep — stronger than any supplement.

Remove what unsettles the night. Coffee and strong tea before 2 pm, and no alcohol in the evening: it makes you drowsy but breaks up the second half of the night.

Check your iron if your periods are heavy. Heavy periods are the most common cause of iron deficiency in women, and iron stores fall before routine blood tests change. Tiredness, breathlessness on the stairs, hair loss — a reason to ask your doctor for a ferritin test. Iron should be taken based on a test, not blindly.

When to see a doctor without delay

• You need to change a pad or tampon every hour for several hours in a row.
• Your period lasts longer than 8 days.
• Bleeding between periods.
• Bleeding together with severe tiredness or feeling faint.

This is not "just the transition" — these signs need to be seen by a gynaecologist.

What to try this week

• Log the first day of your period and your sleep in VIA-L.
• Get up at the same time all seven days.
• Coffee before 2 pm, an evening without alcohol.

This is general information, not a prescription. Tests and treatment are chosen by a doctor.