1 / Why Am I So Tired? Understanding Fatigue After 45

There is tired, and then there is tired.

The kind where you wake up already exhausted. Where coffee gets you functioning but never really energetic. Where you can do what needs to be done, but everything requires more effort than it used to. Perhaps you are sleeping eight hours and still don't feel restored, or you are reasonably functional in the morning and completely depleted by mid-afternoon.

It is tempting to call all of this menopause fatigue. Hormonal changes can absolutely contribute, particularly through disrupted sleep and other menopause symptoms. But fatigue is not a diagnosis, and after 45 I don't want us automatically blaming estrogen, cortisol or ageing.

I want to know what kind of fatigue you have and what is producing it.

First, what do you actually mean by tired?

This is one of the first distinctions I would make if you were sitting in front of me.

Sleepiness means you struggle to stay awake. You might nod off watching television, reading or sitting quietly during the day. That immediately makes me think about sleep quantity, sleep quality, medications and sleep disorders such as obstructive sleep apnoea.

Physical fatigue feels different. Your body feels heavy, exercise feels unusually difficult, your muscles tire quickly or ordinary physical tasks require more effort than they should. Here I start thinking about iron and anaemia, thyroid function, nutrition, illness, cardiovascular or respiratory problems, physical deconditioning and other causes.

Mental fatigue often presents as difficulty concentrating, slower thinking, poor memory or that familiar feeling of having a brain that simply refuses to cooperate.

And then there is low motivation or loss of drive, which can accompany exhaustion but can also occur with depression, chronic stress and other psychological or physiological problems.

These can overlap, of course. But asking what "tired" actually feels like gives us our first clue.

Energy is not something your body simply has

At cellular level, energy ultimately depends on the production and use of ATP, adenosine triphosphate, the molecule cells use to power biological work.

Much of ATP production takes place inside mitochondria. Carbohydrates and fats are broken down through interconnected metabolic pathways, generating molecules that feed into the citric acid cycle and the mitochondrial electron transport chain. Oxygen is ultimately required for efficient oxidative phosphorylation, where large amounts of ATP are produced.

That means energy production depends on far more than eating an "energy boosting" food.

You need adequate fuel. You need oxygen delivery. You need iron and other micronutrients involved in enzymes and electron transport. You need functioning thyroid signalling because thyroid hormones influence metabolic activity throughout the body. You need healthy mitochondria and muscle. You need sleep and recovery.

When any part of that system is compromised, fatigue can be one of the signals.

This is why I don't believe there is one menopause supplement that can meaningfully "fix energy."

There are too many possible bottlenecks.

Start with sleep, even if you think you sleep enough

Before looking for exotic causes of fatigue, I want to know what happens between going to bed and getting up.

Not simply how many hours you spend in bed.

Menopause can disrupt sleep in several ways. Hot flushes and night sweats can repeatedly wake you. Anxiety and mood changes can make it difficult to fall or stay asleep. Restless legs can interfere with sleep, and insomnia can occur independently of vasomotor symptoms.

The result can be sleep fragmentation. You may technically have been in bed for eight hours but have had insufficient restorative sleep.

This matters because poor sleep does much more than make you sleepy. It affects cognition, mood, appetite regulation, glucose metabolism, physical performance and how difficult ordinary tasks feel the following day.

So when a woman tells me she is exhausted, I don't just ask:

"How many hours do you sleep?"

I want to know:

Do you wake refreshed?

That is a much better question.

Don't miss sleep apnoea

This deserves particular attention because women don't always fit the stereotype of the overweight middle-aged man who snores loudly.

Obstructive sleep apnoea occurs when the upper airway repeatedly narrows or closes during sleep. Breathing is interrupted, oxygen levels can fall and the brain repeatedly activates sufficiently to reopen the airway.

You may not remember any of this happening.

Instead, you wake feeling as though you haven't slept.

Snoring, witnessed pauses in breathing, waking gasping, morning headaches, dry mouth, nocturia and excessive daytime sleepiness can be clues, but women may also present with less obvious symptoms such as insomnia, fatigue or mood disturbance.

Risk increases with age, body weight and other anatomical and physiological factors, and sleep-disordered breathing becomes increasingly relevant around and after menopause.

If you sleep for seven or eight hours and remain persistently exhausted, particularly if you snore or have other risk factors, don't assume you simply need more sleep.

You may need better sleep.

Iron deficiency can make you exhausted before you become anaemic

This is one I particularly want women in perimenopause to understand.

Iron is required to make haemoglobin, which allows red blood cells to transport oxygen. But iron also participates in numerous enzymes involved in cellular metabolism and mitochondrial function.

As iron stores decline, iron deficiency can exist before haemoglobin falls sufficiently for you to be classified as anaemic. Fatigue and poor concentration can occur in iron-deficient women without established anaemia, although fatigue is nonspecific and low iron should be confirmed rather than assumed.

Research also suggests that correcting documented non-anaemic iron deficiency can reduce subjective fatigue in some people.

This becomes especially relevant during perimenopause if periods have become heavier or more prolonged.

If someone checks only your haemoglobin and tells you that you are not anaemic, that does not necessarily tell us whether your iron stores are adequate.

That is why ferritin, and when appropriate a fuller assessment of iron status, matters.

And if iron deficiency is found, the next question is not simply which iron supplement to take.

It is why are you losing or failing to absorb iron?

Heavy menstrual bleeding, inadequate dietary intake, gastrointestinal blood loss and malabsorption are among the possibilities that may need investigating.

Your thyroid can look remarkably like menopause

Thyroid hormones regulate metabolic processes throughout the body, so hypothyroidism can produce a remarkably familiar collection of symptoms: fatigue, changes in weight, low mood, constipation, cold intolerance, dry skin, hair changes and cognitive slowing.

Some of those overlap almost perfectly with complaints women develop during midlife.

That does not mean every tired woman has a thyroid disorder.

It means we should not automatically attribute those symptoms to menopause without considering thyroid function, particularly when the clinical picture fits.

There is another reason this matters.

You can be perimenopausal and hypothyroid at the same time.

Finding one does not exclude the other.

Blood sugar swings and insulin resistance can affect how energetic you feel

Glucose is an important fuel, but the relationship between glucose and fatigue is more complicated than "low blood sugar makes you tired."

Insulin allows glucose to be taken up and used or stored by tissues. As insulin sensitivity deteriorates, the pancreas may compensate by producing more insulin to maintain glucose within an acceptable range.

This means metabolic dysfunction can begin before fasting glucose becomes frankly abnormal.

But I would also be careful not to blame every 3 pm energy crash on insulin resistance. Fatigue after lunch can be influenced by meal composition and size, sleep deprivation, circadian biology and simply being awake for several hours.

What makes me look more closely at metabolic health is the bigger pattern: increasing abdominal adiposity, strong family history of type 2 diabetes, elevated triglycerides, hypertension, previous gestational diabetes, polycystic ovary syndrome or abnormal glucose markers.

The menopause transition itself is associated with changes in body composition, including increasing visceral fat and declining lean mass, which can contribute to a less favourable metabolic environment. But the relationship between menopause itself and insulin resistance is complex, with ageing and changes in body composition contributing substantially.

So once again, don't guess.

Look at the whole metabolic picture.

Under-eating can leave you just as exhausted as overeating

This is particularly relevant after 45 because many women respond to weight gain by progressively eating less.

Breakfast disappears. Carbohydrates are removed. Fasting windows become longer. Lunch becomes something tiny because you are "being good." Then you attempt a hard workout while running on coffee and determination.

Your body still requires energy and nutrients.

Chronic inadequate energy intake can impair recovery and physical performance, and inadequate protein and micronutrient intake can compound the problem.

Carbohydrate also has a legitimate physiological role. Glucose is an important fuel, particularly for higher-intensity exercise, and stored glycogen provides readily available carbohydrate in muscle and liver.

This does not mean you need to eat enormous amounts of carbohydrate to have energy.

It means food is not the enemy of energy production. It is one of its requirements.

If you are permanently exhausted while simultaneously restricting food, fasting aggressively and exercising hard, the answer may not be another supplement designed to increase energy.

Your body may need more resources, not another demand.

B12, folate and other nutrients matter, but don't turn fatigue into a supplement hunt

Vitamin B12 and folate are required for normal red blood cell production, DNA synthesis and neurological function. B12 deficiency in particular can cause fatigue alongside neurological or cognitive symptoms.

Deficiency becomes more likely with certain dietary patterns, gastrointestinal conditions, malabsorption and some medications.

Other nutrients participate in energy metabolism too. Magnesium is involved in hundreds of enzymatic reactions, including reactions involving ATP. Iron is essential to mitochondrial electron transport. B vitamins participate as cofactors throughout cellular metabolism.

But there is an important difference between saying a nutrient is involved in energy production and saying taking more of it gives you more energy.

If you are deficient, correcting that deficiency matters.

If you are already sufficient, taking increasingly large doses does not turn mitochondria into tiny turbochargers.

This is why targeted assessment makes more sense than buying a supplement containing every nutrient associated with the word "energy."

Chronic stress can feel like physical exhaustion

Stress is not imaginary and it is not "just in your head."

The brain, autonomic nervous system and hypothalamic pituitary adrenal axis coordinate physiological responses to threat and demand. Cortisol, adrenaline and other signalling systems help mobilise energy and maintain function when something requires action.

That response is useful.

What becomes difficult is prolonged demand with insufficient recovery.

Add poor sleep, work pressure, caregiving, emotional stress, restrictive dieting, excessive exercise, pain or illness and eventually a woman may describe herself as completely depleted.

But I want to be careful with the language here.

Feeling exhausted does not automatically mean you have "adrenal fatigue." The adrenal glands do not simply become tired because you have been stressed.

True adrenal insufficiency is a medical endocrine disorder and is very different from the nonspecific fatigue often marketed online as adrenal fatigue.

What we can have is a chronically overloaded human being with inadequate recovery.

And that is physiologically meaningful without inventing a disease.

Menopause can contribute without being the whole explanation

So where do estrogen and progesterone fit?

They matter.

Hormonal fluctuations during perimenopause can contribute to hot flushes, night sweats, mood changes and sleep disturbance. If you are waking repeatedly because you are drenched in sweat, it is hardly surprising that you are exhausted the following day.

The menopause transition is also associated with changes in body composition, including increased fat mass and declining lean mass, while ageing itself affects muscle and physical capacity.

But I don't want to reduce fatigue to "your estrogen is low."

Sometimes menopause contributes indirectly. Hormonal change disrupts sleep, sleep deprivation affects mood and glucose regulation, exhaustion reduces physical activity, physical conditioning declines and everything starts feeding into everything else.

And sometimes fatigue has very little to do with menopause at all.

That distinction matters because treatment depends on the cause.

Medication deserves a look too

This is easily overlooked.

Some antihistamines, sedatives, pain medications, antidepressants, blood pressure medications and other drugs can contribute to fatigue or sleepiness in some people.

Alcohol can do the same indirectly by disrupting sleep quality even when it initially makes falling asleep easier.

So if fatigue appeared after starting or changing a medication, that timing matters.

Never stop prescribed medication because you think it may be making you tired. But do bring it into the conversation with your doctor or pharmacist.

A proper fatigue assessment includes medications and substances, not just blood tests.

And sometimes fatigue needs medical attention

Persistent or unexplained fatigue should not simply be accepted as part of getting older.

Fatigue accompanied by unexplained weight loss, persistent fever, significant shortness of breath, chest pain, fainting, new neurological symptoms, unusual bleeding or a major unexplained deterioration in your ability to function deserves medical assessment.

So does fatigue that is severe, persistent or clearly different from your normal baseline.

There is a time for lifestyle optimisation.

And there is a time to investigate.

Knowing the difference is part of taking good care of yourself.

The question isn't "How do I get more energy?"

By now I hope you can see why that question is too broad.

A woman losing iron through heavy periods does not need the same intervention as a woman with obstructive sleep apnoea.

Someone chronically under-eating does not need the same plan as someone developing hypothyroidism.

A woman whose night sweats wake her six times a night has a different problem from a woman who sleeps beautifully but becomes exhausted after minimal exertion.

Fatigue is information.

Instead of immediately trying to suppress it with caffeine, supplements or sheer determination, we need to understand what the body is trying to tell us.

And that is exactly where we go next.

Which biomarkers I recommend checking

Not every tired woman needs every blood test. Testing should be guided by symptoms, history, diet, medications and risk factors.

Depending on the clinical picture, I commonly consider a full blood count and ferritin, with additional iron studies where appropriate; TSH and free T4 for thyroid function; fasting glucose and HbA1c, with fasting insulin where it adds useful metabolic information; and vitamin B12, folate and vitamin D when symptoms or risk factors justify testing.

Renal function, liver function and electrolytes can also be relevant in persistent unexplained fatigue, with additional investigations determined by the individual.

And remember: blood tests cannot diagnose poor sleep. If symptoms suggest obstructive sleep apnoea or another sleep disorder, a proper sleep assessment may be more valuable than another tube of blood. Clinical guidance on fatigue likewise recommends history-directed testing rather than indiscriminate laboratory panels.

Your next step

Before trying to "boost" your energy, identify what kind of tired you are. Notice whether you wake refreshed, when your energy falls, whether physical exertion has become harder, whether your periods are heavy and whether food, sleep, stress or medication seem connected to the pattern.

In the next article, we will turn that information into an action plan and answer the much more useful question:

I'm exhausted. Where do I start?

You can also explore more articles, free and paid resources, my book and programmes in the Energy & Fatigue section of Feel Good Menopause.