7 Overlooked Causes Behind Fatigue, Anxiety, and Depression
If you’ve been feeling tired, anxious, or just not like yourself lately, you’re not alone.
Most people are told it’s:
stress
burnout
hormones
or “just life”
And while those things can be part of the picture… they’re often not the whole story. Because underneath how you feel, there’s usually something deeper going on physiologically.
Here are 7 commonly overlooked root causes I see behind fatigue, anxiety, and low mood, especially in women.
1. Low Iron (Even Without Anemia)
This is one of the biggest ones, and one of the most missed.
You don’t have to be anemic to feel the effects of low iron. Low ferritin (your iron stores) alone can lead to:
Fatigue that doesn’t improve with rest
Anxiety or that “on edge” feeling
Hair shedding
Poor focus and brain fog
Iron is essential for oxygen delivery and brain function. When it’s low, your body is literally running on less fuel. And yet, most people are only told they’re “fine” because their hemoglobin is normal.
2. Blood Sugar Imbalances
This one shows up as the classic: tired → wired → crash → crave → repeat
When your blood sugar isn’t stable, your body has to constantly compensate — often by releasing stress hormones like cortisol and adrenaline.
This can feel like:
Anxiety or jitteriness
Energy crashes mid-day
Irritability
Poor concentration
A lot of people think they’re dealing with anxiety, when it’s actually unstable blood sugar driving the symptoms.
3. Chronic Stress + Nervous System Dysregulation
This is the piece people do talk about, but often not deeply enough.
When your body is stuck in a chronic stress state:
Cortisol stays elevated (or eventually becomes dysregulated)
Your nervous system stays in “fight or flight”
Your body struggles to fully rest and recover
This can look like:
Feeling tired but wired
Trouble sleeping or staying asleep
Anxiety without a clear trigger
Burnout that doesn’t resolve with time off
At a certain point, it’s not just stress, it’s a nervous system pattern.
4. Nutrient Deficiencies (Beyond Iron)
There are a handful of nutrients that directly impact energy and mood, and many women are low in them without realizing.
The most common:
Vitamin B12 → energy, mood, brain function
Vitamin D → mood, immune health
Magnesium → nervous system regulation, sleep
Zinc → brain health + immune support
When these are low, your body doesn’t have what it needs to produce energy or regulate mood properly.
And again, this often gets missed in basic testing.
5. Thyroid Dysfunction (Even Subtle)
Your thyroid controls your metabolism aka how your body creates and uses energy.
Even mild imbalances can show up as:
Fatigue
Depression or low motivation
Brain fog
Weight changes
Feeling cold or sluggish
The issue is most people only have TSH tested, which doesn’t always tell the full story. You can be told your thyroid is “normal” and still be struggling with symptoms.
6. Inflammation (The Silent Driver)
Inflammation isn’t always obvious, but it has a huge impact on how you feel.
Low-grade, chronic inflammation can contribute to:
Fatigue
Low mood
Brain fog
Anxiety
It can be driven by:
Gut imbalances
Food sensitivities
Chronic stress
Poor sleep
This is often the underlying layer connecting multiple symptoms together.
7. Gut Health Imbalances
Your gut and brain are constantly communicating, which means your digestion directly affects your mood and energy.
When your gut is off, you might experience:
Anxiety or low mood
Fatigue after eating
Bloating or digestive issues
Brain fog
This is partly because a large portion of your neurotransmitters (like serotonin) are influenced by your gut.
So if your gut isn’t supported, your mood won’t be either.
The Takeaway
Fatigue, anxiety, and depression are rarely random. They’re often your body’s way of saying: something is out of balance.
And when you start to look at things like:
iron
nutrients
blood sugar
hormones
gut health
nervous system
…you move from guessing → to actually understanding what’s going on.
