Tired All the Time in Perimenopause: What to Rule Out Before You Blame Hormones

Somewhere in your late thirties or forties, a sentence arrives and then never leaves. It is probably just your hormones.

Sometimes that is exactly right. Perimenopause starts earlier than most people expect, it can run for years, and fatigue is one of its least-discussed features. It genuinely explains a great deal.

The trouble is what happens once the explanation arrives. It tends to close the conversation rather than open it, and several other things that cause identical tiredness quietly stop being looked for. Not because anyone is careless, but because a plausible answer is very hard to keep questioning.

So this is the order I would go in.

First, is it actually perimenopause?

Fatigue on its own is thin evidence. Perimenopause is much more convincing when the tiredness has arrived alongside other changes.

Periods that have changed in length, heaviness or predictability. Sleep that breaks in the small hours when it never used to. Night sweats. Mood or anxiety that feels unfamiliar rather than like your usual self on a bad week. Joint aches. A memory that has become annoying.

Tiredness plus three or four of those is a pattern. Tiredness on its own, with a cycle that has not altered at all, is a symptom looking for a cause, and it is too early to settle on this one.

The four things to rule out first

1. Iron stores. Top of the list, and it is not close. Periods are the largest ongoing draw on iron most women have, and in perimenopause they often get heavier before they stop. So the very thing being blamed for the tiredness is also increasing the most common cause of it. Ferritin has to be asked for; a standard blood count does not include it.

2. Thyroid. Thyroid conditions become more common with age and the symptoms overlap almost completely. Usually already checked, and the number is worth having rather than the word.

3. Blood sugar over time. Not a one-off fasting reading. HbA1c gives an average across roughly three months, and insulin resistance builds quietly for years while producing exactly this kind of flat, heavy tiredness.

4. Vitamin D and B12. Both have wide reference ranges, both affect energy and concentration, and in a British winter low vitamin D is an ordinary finding rather than an exotic one.

None of these is exciting. All four are cheap, and any one of them can be the whole answer.

The two nobody tests for

Sleep quality, as distinct from sleep hours. Eight hours of broken sleep is not eight hours of sleep. If you are waking at three or four most nights, you are living on fragments, and no blood test will show that. It is also one of the things perimenopause reliably does.

What you are actually eating. Not a diet question. Most women eating "sensibly" while busy are running on far less protein than they think, and protein is what keeps energy level across a day. If breakfast is coffee and lunch is whatever is nearest, that is worth fixing before anything more complicated.

Before you reach for a supplement

Do not start iron on a hunch. Too much causes its own problems and taking it blind can hide the very thing that needed finding. Get the number first, then decide.

The same goes for iodine and thyroid. Do not treat a gland you have not had assessed.

What actually helps, whatever the cause

These are worth doing while you wait for answers, because they help across almost every cause on this page.

Protein at breakfast. It is the single change with the most reliable effect on how the rest of the day feels.

Daylight early. Ten minutes outside in the morning helps set the rhythm that governs your overnight cortisol, which is the thing waking you at three.

Resistance training twice a week. It protects muscle through perimenopause, and muscle is where a great deal of your day-to-day energy capacity lives.

Honesty about alcohol. It gets you to sleep and then wakes you in the small hours, and in perimenopause most women notice it stops agreeing with them somewhere along the way.

Then, and only then, the hormone conversation

Once the four cheap things have been ruled out and the sleep and food are not obviously the problem, perimenopause becomes a much stronger explanation. And at that point it is a genuinely useful one, because there is something to discuss.

That conversation goes better when you arrive with your figures, a note of how your cycle has changed, and a clear account of what has already been excluded.

Which is the whole point. Blaming hormones too early costs you the four cheap answers. Refusing to consider hormones at all costs you the right one.

This is general information, not personal medical advice, and it is not a substitute for seeing your own doctor. If you want someone to look at your own situation properly, that is what the Women's Health Consultation is for.