It Wasn’t Them. It Was Me. And Also My Blood Sugars.
I have mood swings. All the time. That’s just the reality of living with T1D.
They arrive without warning — the irritability, the short fuse, the disproportionate reactions to things that wouldn’t normally register. And in the early years, before I understood the connection clearly and before the people around me understood it at all, they caused damage. I hurt people I cared about. Said things in states of blood-sugar-driven dysregulation that I wouldn’t have said otherwise.
It took time — a significant amount of time — for the people in my life to understand that what was happening in those moments genuinely wasn’t about them. That the irritability wasn’t a comment on them or on the relationship. That the person in front of them during a mood swing wasn’t the person they thought they knew — not because I was hiding something, but because my blood sugar was doing something specific that was temporarily making me someone other than myself.
What’s Actually Happening
When blood sugar drops, the body releases adrenaline and cortisol — the same hormones that drive the fight-or-flight response. The result is irritability, anxiety, disproportionate emotional reactivity. Not because anything is actually wrong with the situation, but because the brain is operating under conditions of physiological stress.
When blood sugar rises significantly, the effects are different but also real: lethargy, low mood, difficulty concentrating, a heaviness that can look like depression and feel like one too.
And the swings between the two — the rollercoaster of highs and lows that many T1Ds experience, particularly during difficult management periods — produce a kind of sustained emotional instability that is exhausting for the person experiencing it and confusing for everyone around them.
This is not a personality issue. It is a physiological reality. The mood is a symptom, not a character flaw.
What Makes It Harder
The unpredictability is the hardest part.
A mood swing driven by blood sugar doesn’t announce itself with a clear warning. It arrives. And by the time you’ve noticed it, you may already have said or done something that’s caused damage — snapped at someone, withdrawn, reacted to something small as though it were large.
The recognition usually comes after. When the blood sugar settles, when the cortisol drops, when you look back at the last hour and can see what was happening. By which point the damage, if any was done, is already there.
Learning to recognise the early signs — the particular quality of irritability that comes from blood sugar rather than genuine grievance, the specific feeling of a low arriving before the CGM catches it — takes years. And even then, it’s imperfect.
What Helps
Telling the people in your life what’s happening — honestly, specifically — makes a significant difference. Not as an excuse for the mood swings, but as context. “Sometimes my blood sugar affects my mood in ways I can’t fully control. If I seem irritable or withdrawn, please don’t take it personally — check in with me and give me a moment.”
That conversation, had in a calm moment rather than in the middle of a swing, changes how the people around you respond. It gives them a frame. And having people respond with concern rather than hurt or confusion reduces the secondary damage that the mood swings produce.
Tracking the pattern — noticing which blood sugar states produce which emotional states in you specifically — builds the self-awareness to catch the swing earlier. It won’t stop it. But it helps you name it sooner, which reduces its power.
And forgiving yourself for the impact, while taking responsibility for it, is the balance that matters. The mood swing is not your fault. The relationship repair after it is your responsibility. Both of those things are true.
Causes…
What Causes Diabetes Mood Swings?
Blood Sugar Is a Tiny Tyrant
Fluctuations in blood glucose levels can mess with your brain chemistry. Highs can make you foggy or angry. Lows can bring anxiety, tears, or full-blown rage at your Wi-Fi for buffering.
The Mental Load of Diabetes
Worrying about A1C results, meal planning, or whether you packed a snack… it all adds up. The stress of constant vigilance wears down your emotional resilience.
Medications and Hormones
Some diabetes meds, especially insulin and certain GLP-1s, can affect mood. And don’t forget the hormonal chaos diabetes can stir up, especially for women dealing with menstrual cycles or menopause.
What It Feels Like When It Hits
Sudden Rage, Sadness or Panic
You’re fine one moment, then BAM—tears over spilt tea. Or white-hot fury because someone left the fridge open. That’s not just stress. That’s a biochemical storm brewing.
You’re Not Just Moody—You’re Biochemically Hijacked
Let’s stop shaming ourselves. You’re not being dramatic or unstable. Your brain is simply reacting to a changing internal environment. Still doesn’t mean you get to scream at your boss, though.
The Collateral Damage: Relationships
Mood Swings Aren’t Private
The worst part? These swings don’t just affect you—they hit everyone around you. Your loved ones may start tiptoeing around your moods, or worse, taking it personally.
How to Explain Without Shame
Tell people what’s really happening: “Hey, sometimes my blood sugar messes with my head. It’s not about you. It’s a medical thing.” That alone can open doors to more patience and support.
What You Can Do About It
Track Your Moods and Glucose Together
Patterns will appear. You might notice that every time you drop below 4.0 mmol/L, you want to cry about climate change. That’s data you can work with.
Build a Mood-Buffer Routine
Eat regularly. Sleep properly. Move your body. Don’t wait for chaos to strike—build stability before the swing hits.
Feed Your Brain, Not Just Your Belly
Low-GI foods, fiber, healthy fats. Less sugar. More greens. Your brain needs the same things your pancreas does: consistency.
Move Your Body—Even a Little
A 10-minute walk can clear your head and balance your blood sugar. You don’t need a gym. You need fresh air and a break from doomscrolling.
Sleep Like Your Life Depends On It
Because it does. No sleep = hormonal anarchy = even worse diabetes mood swings.
Try Breathing (Yes, Really)
Mindfulness isn’t woo. Just five slow breaths can switch off panic mode. It’s free. It’s fast. And you can do it anywhere—even on the toilet.
Don’t Try to Handle It Alone
Talk to Your Diabetes Team
If your mood swings are out of control or feel scary, bring it up. This is just as important as your A1C.
Therapy Is Not Weak
A diabetes-aware therapist can help you untangle years of stress, guilt, and shame—and give you tools to survive future diabetes mood swings.
Peer Support Is Gold
Find a community that gets it. Online groups, in-person meetups, even Reddit. You are NOT the only one slamming doors at 4.3 mmol/L.
When It Gets Scary
You Feel Unsafe or Spiraling
If your thoughts get dark or dangerous, seek emergency help. Don’t wait. Call a crisis helpline or get to A&E. This is urgent, and you matter.
Want More Support?
Managing your head is just as important as managing your glucose. That’s what I help with. Book a free Discovery Call today to see if we can’t work together.
Useful External Links
Yours,
Pete
