Perimenopause
Is there a test for perimenopause?
Quick answer
For most women over 45, there is no single test that confirms perimenopause, and one usually isn’t needed. UK guidance from NICE says doctors can diagnose it from symptoms and changes to your periods, because the hormone most tests measure (FSH) rises and falls from day to day. Blood tests are more useful between 40 and 45, under 40, or to rule out other causes. Home kits measure the same fluctuating hormone. A clear record of your symptoms over a few months is often the most useful evidence you can bring.
What might be happening
In perimenopause your ovaries do not wind down in a straight line. Follicle-stimulating hormone (FSH), estrogen and progesterone can swing widely from one week to the next, so a single blood sample can come back "normal" on a day you feel awful, or raised in a month that then settles. NICE notes that FSH fluctuates considerably over short periods in the years before menopause, which is why it advises against using FSH or other hormone tests to diagnose perimenopause in otherwise healthy women over 45.
Instead, for women over 45, NICE says perimenopause can be diagnosed from symptoms such as hot flashes or night sweats together with irregular periods, and menopause after 12 months without a period. Most home menopause tests check FSH in urine, so they share the same limitation: a positive result suggests your hormones are changing, and a negative one does not rule perimenopause out.
Tests still have a role. A doctor may consider an FSH test if you are 40 to 45 with symptoms and cycle changes, and if you are under 40, two blood tests a few weeks apart help check for premature ovarian insufficiency. Blood tests such as thyroid function or a blood count can also rule out other causes of tiredness, mood changes or heavy bleeding. Hormonal contraception can mask period changes and affect results, which is worth mentioning.
What to notice
- Your period dates, cycle length and flow over at least two or three months.
- Hot flashes and night sweats: how often, and how strong.
- Sleep: trouble falling asleep, waking in the night, or early waking.
- Mood, anxiety, irritability and concentration.
- Other changes: joint aches, headaches, skin, hair, bladder or libido.
- Any hormonal contraception or medicines you take, and when they started.
This is the information NICE guidance uses to diagnose perimenopause in women over 45, so writing it down as it happens is far more reliable than remembering it in the appointment.
Related patterns
Symptoms that overlap with perimenopause, and that a doctor may want to rule out, include:
- tiredness, weight change or feeling cold (thyroid changes)
- tiredness and breathlessness with heavy periods (low iron or anemia)
- low mood or anxiety with a different pattern to your cycle
- side effects from a new medicine or contraception
Ruling these out is one of the main reasons for a blood test in your 40s, rather than confirming perimenopause itself.
Notice the pattern
Because perimenopause is diagnosed mainly from your history, the quality of that history matters. Symptoms that come and go, or move with your cycle, are easy to forget or understate in a short appointment.
A few months of notes showing what changed, when, and how much it affects your days gives a doctor the picture a single blood test cannot.
When to get support
Speak to a doctor if:
- you are under 40 and your periods have changed or stopped, or you have hot flashes
- you are 40 to 45 with symptoms and changes to your cycle
- your periods are very heavy, or you bleed between periods or after sex
- you bleed again after 12 months without a period
- symptoms are affecting your sleep, work, mood or relationships
If you are told you are "too young" or "your bloods are normal", it is reasonable to ask how the guidance applies to you and to share your symptom record.