Table of Contents
It starts with something small.
You forget a word halfway through a sentence.
Not a complicated word. A normal one.
The name of a colleague. The thing you went into the kitchen to get. The reason you opened your phone. A sentence you were halfway through saying before it disappeared completely.
You laugh it off the first time.
Then it happens again.
And again.
At the same time, sleep changes. You used to fall asleep easily, but now you wake at 3:00 AM with your mind racing. Your period still comes every month, but the timing is different. Maybe the cycle is shorter. Maybe the bleeding is heavier. Maybe PMS has become more intense than it used to be.
You feel irritated, foggy, emotional, tired, wired, and strangely unlike yourself.
But you are only 38.
So you assume it must be stress.
Work. Children. Money. Lack of sleep. Too much coffee. Not enough exercise. Too much exercise. Maybe anxiety.
Maybe burnout.
And sometimes it is those things.
But sometimes, in the late 30s and early 40s, hormone changes begin before anyone expects them to.
That is what makes early perimenopause so confusing.
It can arrive while your periods are still showing up.
Quick answer
Perimenopause usually begins in the 40s, but some women notice hormone-related changes in their late 30s. Symptoms can include brain fog, poor sleep, mood swings, anxiety, heavier or shorter cycles, night sweats, hot flushes, headaches, lower libido, vaginal dryness or urinary symptoms. If symptoms begin before 40, it is important to speak with a doctor because premature ovarian insufficiency, thyroid disease, iron deficiency, pregnancy, PCOS, stress, depression and other causes may need to be ruled out.
Perimenopause is not one sudden event
Many women grow up thinking menopause is a switch.
One day periods stop.
Then hot flushes begin.
Then it is “menopause”.
But that is not how it usually works.
Menopause is technically reached after 12 months without a period. Perimenopause is the transition leading up to that point, when hormones fluctuate and symptoms may begin.
The tricky part is that perimenopause can last for years.
And during that time, periods may still arrive.
That is why so many women miss it. They think, “I can’t be perimenopausal because I still get my period.”
But perimenopause is not defined by your period disappearing overnight.
It often begins with change.
Shorter cycles.
Longer cycles.
Heavier bleeding.
Sleep disruption.
Mood changes.
Brain fog.
Hot flushes or night sweats.
Symptoms that seem to move around without a clear pattern.
You are not imagining it just because your calendar still has a monthly bleed.
Why brain fog can feel so frightening
Brain fog is one of the symptoms women often find hardest to explain.
It is not just being busy.
It is not simply walking into a room and forgetting why.
It can feel like your brain is buffering.
You lose words.
You reread the same email three times.
You forget appointments unless they are written down.
You feel slower at work.
You cannot hold as many mental tabs open as before.
You worry people will notice.
For women who have always been organised, sharp and reliable, this can be deeply unsettling. It can feel like losing part of your identity.
Hormone changes may contribute to cognitive symptoms in some women, especially when they also affect sleep and mood. But brain fog can also be caused by other issues such as low iron, low B12, thyroid problems, poor sleep, anxiety, depression, ADHD, medications, alcohol, long COVID, burnout or blood sugar problems.
That is why it should not be dismissed as “just hormones”.
But it also should not be dismissed as “just stress”.
It deserves a proper conversation.
The sleep change nobody warns you about
For many women, sleep is the first major sign that something has shifted.
Not always trouble falling asleep.
Sometimes it is waking suddenly in the early hours.
2:47 AM.
3:12 AM.
4:03 AM.
Wide awake.
Mind switched on.
Body tired but alert.
You may wake hot, sweaty, anxious, thirsty, restless or just strangely awake for no reason.
Then the day starts badly because you are exhausted before it has even begun.
Poor sleep then makes everything else worse. Brain fog gets heavier. Mood becomes more fragile. Cravings increase. Exercise feels harder. Work feels more overwhelming. PMS feels bigger.
This is why perimenopause can be mistaken for burnout.
The two can overlap.
But if sleep disruption appears with cycle changes, mood shifts, night sweats, vaginal dryness, breast tenderness, headaches or changing PMS, hormones may be part of the picture.
Your period may still be regular — just different
A common misunderstanding is that perimenopause only begins when periods become wildly irregular.
Sometimes that happens.
But early changes can be more subtle.
You may notice:
- cycles becoming shorter than usual
- bleeding becoming heavier
- spotting before the period
- PMS becoming more intense
- breast tenderness changing
- cramps feeling different
- migraines or headaches around the cycle
- mood changes before bleeding
- sleep getting worse before the period
- anxiety rising at certain cycle points
For example, a woman who always had a 29-day cycle may suddenly notice 24-day cycles. That is still “monthly”, but it is different for her.
That difference matters.
The most useful question is not only, “Are your periods regular?”
It is:
“Have they changed?”
At 38, do not assume — investigate
This is the most important clinical point.
If you are 45 and having classic symptoms, perimenopause may be more likely.
If you are 38, it is possible, but it is also important to rule out other causes.
Menopause before 40 is usually considered premature menopause or premature ovarian insufficiency.
Menopause between 40 and 45 is considered early menopause. These are not just labels. They can have implications for fertility, bone health, heart health and long-term hormone exposure.
So if symptoms suggest ovarian hormone changes before 40, it is worth speaking with a doctor rather than self-diagnosing from TikTok or Instagram.
A doctor may consider questions such as:
Have your cycles changed?
Are you missing periods?
Could you be pregnant?
Are you using hormonal contraception?
Any hot flushes or night sweats?
Any vaginal dryness or painful sex?
Any family history of early menopause?
Any autoimmune conditions?
Any previous chemotherapy, pelvic surgery or ovarian surgery?
Any thyroid symptoms?
Any low iron symptoms?
Any major stress, weight change or overtraining?
Any symptoms of PCOS?
The goal is not to make the appointment scary.
The goal is to stop guessing.
What tests might a doctor consider?
There is no single perfect “perimenopause test”.
Hormones fluctuate, so a one-off hormone blood test can be hard to interpret, especially in typical perimenopause.
But in younger women, especially under 40 or around early menopause age, blood tests may be more useful because the doctor may need to assess for premature ovarian insufficiency or other causes.
Depending on your symptoms, a doctor may consider:
- pregnancy test
- thyroid function
- full blood count
- iron studies and ferritin
- B12 and folate
- vitamin D
- FSH and oestradiol in selected cases
- prolactin if periods are absent or irregular
- androgen testing if PCOS symptoms are present
- glucose or HbA1c if metabolic symptoms are present
- pelvic ultrasound if bleeding patterns require investigation
Not everyone needs all of these.
The right tests depend on the pattern.
But if you are 38 and suddenly foggy, sleepless, emotionally volatile and your cycles are changing, it is reasonable to ask for a proper review.
Symptoms that may point toward perimenopause
Perimenopause can look different from woman to woman.
Some women mainly get hot flushes.
Some mainly get mood symptoms.
Some mainly lose sleep.
Some mainly notice their cycles shortening.
Others feel like their whole nervous system has become more sensitive.
Possible symptoms include:
- brain fog
- word-finding difficulty
- poor concentration
- sudden insomnia
- night sweats
- hot flushes
- heavier periods
- shorter or irregular cycles
- worse PMS
- anxiety or panic-like feelings
- irritability or mood swings
- headaches or migraines
- breast tenderness
- joint aches
- lower libido
- vaginal dryness
- painful sex
- urinary urgency or recurrent UTIs
- weight distribution changes
The presence of one symptom does not prove perimenopause.
The pattern is what matters.
Why women feel like they are “losing their minds”
One of the cruelest parts of early perimenopause is that the symptoms can look psychological.
Anxiety.
Irritability.
Low mood.
Poor concentration.
Sleep disruption.
Overwhelm.
Tearfulness.
Rage before a period.
Many women are told they are stressed, depressed, too busy, not coping, or need to meditate.
Sometimes mental health support is absolutely helpful. But if mood symptoms have appeared alongside cycle changes, night waking, hot flushes, heavier bleeding, brain fog or vaginal symptoms, hormonal transition should at least be considered.
You can be stressed and perimenopausal.
You can have anxiety and hormone-related sleep disruption.
You can need therapy and medical assessment.
It does not have to be one or the other.
What can help?
Treatment depends on the person, age, symptoms, medical history, contraception needs and whether early menopause or premature ovarian insufficiency is suspected.
Options may include:
- sleep support and routine changes
- reducing alcohol if it worsens night waking
- strength training and regular movement
- nutrition support, especially protein, iron and calcium
- stress management that is realistic, not patronising
- treating low iron, thyroid issues or deficiencies if found
- managing heavy bleeding
- considering contraception needs
- discussing menopause hormone therapy or other hormonal options where appropriate
- non-hormonal options for symptoms if hormones are not suitable
- mental health support if mood symptoms are significant
This is not a “just take hormones” article.
Hormone therapy is helpful for some women and not suitable for others. The right decision depends on clinical assessment.
But women should know that support exists.
They should not be told to simply push through.
Can telehealth help?
For many women, yes — especially as a first step.
A telehealth doctor can take a detailed history, ask about cycle changes, sleep, mood, bleeding, contraception, pregnancy risk, family history, and symptoms that may need urgent or in-person review.
Through Doctor Help, you can book a private telehealth consultation with an Australian-registered doctor. Where clinically appropriate, the doctor may arrange pathology testing, discuss possible causes of brain fog and cycle changes, and advise whether in-person review, pelvic examination, ultrasound or specialist referral may be needed.
Telehealth cannot replace every women’s health assessment.
But it can help you stop sitting alone with the thought:
“Am I going crazy, or is something changing?”
When to seek medical review sooner
You should speak with a doctor if you have:
- symptoms before age 40 that suggest hormone changes
- missed periods or major cycle changes
- very heavy bleeding
- bleeding between periods
- bleeding after sex
- severe new headaches
- sudden mood changes affecting safety or daily life
- hot flushes or night sweats before 40
- unexplained fatigue or brain fog
- vaginal dryness, painful sex or recurrent urinary symptoms
- family history of early menopause
- symptoms after chemotherapy, pelvic surgery or ovarian surgery
Seek urgent help if you have thoughts of self-harm, severe pelvic pain, heavy bleeding soaking pads quickly, fainting, chest pain, stroke-like symptoms or sudden severe headache.
You are not too young to ask the question
At 38, many women are in the busiest years of their lives.
Work is demanding.
Children may be young.
Parents may be ageing.
Relationships carry pressure.
Sleep is already fragile.
So when brain fog, insomnia, mood swings and cycle changes appear, it is easy to blame life.
And life may be part of it.
But it may not be the whole story.
Perimenopause is not always a neat event that waits until 50. Hormone changes can begin earlier than many women expect. And if they begin before 40, they deserve proper medical attention, not dismissal.
You are not weak for noticing the change.
You are not dramatic for wanting answers.
And you are not “losing your mind” because your body has stopped feeling predictable.
The smartest next step is not panic.
It is pattern recognition.
Track your cycle. Notice sleep changes. Write down mood shifts, hot flushes, night sweats, brain fog, bleeding changes and physical symptoms. Then take that pattern to a doctor and ask for a proper review.
Because sometimes the sentence “I don’t feel like myself” is not vague at all.
Sometimes it is the first real clue.
FAQs
Can perimenopause start at 38?
It can, but symptoms before 40 should be assessed by a doctor. Menopause before 40 is considered premature menopause or premature ovarian insufficiency, and other causes such as thyroid disease, pregnancy, low iron, PCOS, stress and medication effects may need to be ruled out.
What are early signs of perimenopause in your late 30s?
Possible signs include shorter cycles, heavier bleeding, night waking, brain fog, mood swings, anxiety, hot flushes, night sweats, headaches, breast tenderness, vaginal dryness or changes in PMS.
Can perimenopause cause brain fog?
Some women report difficulty concentrating, forgetfulness and word-finding problems during the menopause transition. Poor sleep, mood changes, low iron, thyroid problems and stress can also cause brain fog, so assessment matters.
Do periods still come during perimenopause?
Yes. During perimenopause, periods can still come every month, but the pattern may change. Cycles may become shorter, longer, heavier, lighter or less predictable.
Is there a blood test for perimenopause?
There is no single perfect test for typical perimenopause because hormone levels fluctuate. However, blood tests may be considered if early or premature menopause is suspected, or to rule out other causes of symptoms.
Can I get hormone-related symptoms checked online?
A telehealth doctor can assess symptoms, review your history and arrange blood tests where clinically appropriate. Some symptoms, such as abnormal bleeding or pelvic pain, may still need in-person examination or imaging.
Disclaimer:
This article provides general information only and does not replace personal medical advice. Brain fog, irregular periods, heavy bleeding, mood changes, insomnia, hot flushes, early menopause symptoms or suspected hormonal changes should be assessed by a qualified healthcare professional. In an emergency, call 000 or attend the nearest emergency department.
References:
- Healthdirect Australia — Menopause
- Jean Hailes — Perimenopause and menopause
- Australasian Menopause Society — Menopause and premature ovarian insufficiency
- Better Health Channel — Menopause
- Monash Centre for Health Research and Implementation — Menopause information
Reviewed By: Dr. Momal Ahmad.
