If you are in your 40s and feeling tired, foggy, irritable, or not quite like yourself, it is easy to assume that perimenopause is the reason. And it may be. But there is another common issue that can cause many of the same symptoms: iron deficiency.
Iron deficiency is common in women during the perimenopausal years, especially when periods become heavier or less predictable. The tricky part is that the symptoms of low iron and perimenopause can look very similar.
This means that some symptoms may be blamed on changing hormones when low iron is also playing a role.
Why are iron levels important during perimenopause?
Iron helps your body make red blood cells and carry oxygen around your body. It is also important for energy production, brain function, and many other processes.
During early and mid-perimenopause, periods can become heavier, longer, or more frequent. You may also have more spotting or unpredictable bleeding. Over time, this blood loss can use up your body's iron stores.
You do not need to have anemia to be low in iron. Iron deficiency can occur before anemia develops. This is an important distinction because many women with low iron may have symptoms even when their hemoglobin is still in the normal range.
Low iron and perimenopause can feel very similar
Some of the most common symptoms of iron deficiency include:
Fatigue and low energy
Brain fog
Trouble concentrating
Feeling less mentally sharp
Irritability or low mood
Reduced exercise tolerance
Headaches
Poor sleep
Restless legs
Now compare that with common perimenopause symptoms.
Many women report:
Fatigue
Brain fog
Mood changes
Anxiety or irritability
Headaches
Sleep problems
Changes in energy
See the problem? There is a lot of overlap.
This is why it can be helpful to look beyond hormones when assessing symptoms during perimenopause.
Heavy periods can make the problem worse
One of the biggest clues is your menstrual pattern.
If your periods have become noticeably heavier or longer, you may be losing more iron than you are replacing.
You may notice:
Needing to change a pad or tampon very frequently
Bleeding through products
Passing larger blood clots
Periods lasting longer than they used to
More frequent periods
Spotting between periods
You can also become iron deficient from menstrual blood loss without realizing just how much iron you are losing over time. And this is particularly important during perimenopause because menstrual patterns can change quite quickly.
You can be iron deficient without being anemic
This is one of the most important things to understand about iron. A standard blood count can tell us whether you have anemia, but it does not always tell us whether your iron stores are healthy.
Ferritin is a useful marker of your body's stored iron.
A person can have a normal hemoglobin level but low or depleted iron stores. This is sometimes called iron deficiency without anemia.
Research suggests that iron deficiency without anemia can still affect energy, concentration, physical capacity, and quality of life. In some women, correcting the iron deficiency can improve unexplained fatigue.
This is why I do not recommend waiting for anemia before considering iron status.
What about restless legs and sleep?
Restless legs are another reason to think about iron. Restless legs syndrome can cause an uncomfortable urge to move the legs, often worse when you are sitting or lying down at night. It can make falling asleep difficult and can lead to poor-quality sleep.
Low iron is strongly associated with restless legs, and studies have found that iron treatment can improve restless leg symptoms in people with iron deficiency.
So if you are experiencing poor sleep plus restless legs, checking your iron status may be worthwhile.
What happens to iron later in the menopause transition?
Interestingly, iron levels can change as you move through menopause. Early in perimenopause, heavier or more frequent periods can cause iron stores to fall.
Once periods stop, menstrual blood loss stops too. As a result, iron stores often begin to rise. This means iron status is not something we should think about as a one-time issue. A woman may be iron deficient during early perimenopause and have a very different iron status several years later after her periods have stopped.
This is one reason that testing should be based on your current symptoms, menstrual history, diet, health history, and stage of the menopause transition.
What should you test?
If you are experiencing significant fatigue, brain fog, poor sleep, restless legs, or reduced exercise tolerance, it may be worth discussing your iron status with your healthcare provider.
This is especially important if you also have heavy or irregular periods.
Depending on your symptoms and health history, testing may include:
CBC (complete blood count)
Ferritin
Transferrin saturation (TSAT)
Other iron studies when appropriate
Should you take an iron supplement?
Not necessarily. Iron is an important nutrient, but more is not always better.
If testing shows that you are iron deficient, oral iron is usually the first treatment. The type, dose, and frequency can be adjusted based on your needs and how well you tolerate it.
Some people experience constipation, nausea, or other digestive symptoms from iron supplements. In certain situations, IV iron may be considered, such as significant ongoing blood loss, poor absorption, or difficulty tolerating oral iron.
The most important step is to understand why you are low in iron in the first place.
For example, if heavy menstrual bleeding is continuing, replacing iron without addressing the blood loss may only be a temporary solution.
The take-home
Perimenopause can explain a lot of symptoms. But it should not automatically explain every symptom.
If you are in your 40s or 50s and struggling with fatigue, brain fog, mood changes, poor sleep, restless legs, or reduced exercise tolerance, it is worth looking at the full picture.
Iron deficiency is common, treatable, and easy to miss.
Checking your iron status can help determine whether your symptoms are related to hormonal changes, low iron, or a combination of both.
If you're curious about iron deficiency, how to test and if you're a good candidate for iron infusions, book a free discovery call to learn more.
In Health,
Dr. Ashley Damm, BSc ND MSCP
Naturopathic Doctor- Women's Health & Fertility