The Blood Sugar Pattern I See Before Almost Every Migraine — What I'm Learning From My CGM

I'm not a migraine researcher. I'm a registered nurse who put a CGM on her own arm because she got tired of guessing.

And what I keep seeing in my own data is hard to ignore.

There's a blood sugar pattern that shows up before almost every migraine I get. I've now watched it happen close to 10 times. Same shape. Same setup. Same crash before the headache hits.

And it's not what I thought it was for years.

What I used to believe

For years, I believed the same thing most women believe: my migraines are from low blood sugar.

That belief is everywhere. "You skipped a meal." "You went too long without eating." "Just have something sweet — you'll feel better."

And honestly? Sometimes that did seem to help — for about 20 minutes. Then the headache would come back worse.

Now I understand why.

What I actually see on my CGM

It's not one big spike. It's not just one low.

It's hours of up and down. Up and down. Up and down.

On the days my migraines hit, my graph looks like a rollercoaster — multiple spikes followed by sharp drops, often for most of the day before the headache shows up. Not gentle waves. Sharp peaks and valleys.

On my migraine-free days? My graph is steadier. Smaller waves. Slower returns to baseline.

Same body. Same person. Different patterns. Different outcomes.

And here's what's wild — the research is starting to show this too

I want to be clear: I'm not a researcher. I'm a nurse looking at her own data. But when I went looking to see if anyone else was seeing what I was seeing — turns out, they are.

In January 2026, a study was published in Frontiers in Neurology called "Glucose dysregulation and glycemic phenotyping in chronic migraine." Researchers used CGMs and oral glucose tolerance tests on chronic migraine patients and compared them to healthy controls.

What they found:

• People with chronic migraine had significantly more glucose variability than people without migraines

• More day-to-day swings. More within-day swings. More post-meal dysregulation.

• It wasn't just about being high or low. It was about how often glucose was moving up and down.

In their words, the swings — the variability — were the pattern. Not just a single low.

That's exactly what I was watching on my own arm.

Why this matters even more in midlife

Here's where it gets interesting for women like me — and probably you, if you're reading this.

Migraines and perimenopause are practically dance partners. Hormonal fluctuations — especially estrogen — are well-documented migraine triggers. And perimenopause is the hormonal rollercoaster years.

But here's what gets missed in most conversations:

Estrogen drops also affect insulin sensitivity. So when your hormones are fluctuating, your blood sugar response gets messier too. Same meal, different days, totally different glucose curves.

That means in midlife, you can be doing all the "right things" — eating regularly, hydrating, sleeping — and STILL have wild blood sugar swings you didn't have in your 30s.

And if you're prone to migraines? Those swings stack on top of the hormone swings. Your brain — which already struggles with energy stability during a migraine — gets a double dose of chaos.

What I now watch for

After almost 10 of these migraines, here's the pattern I now look for on my CGM:

1. A morning spike that doesn't come back down clean

My breakfast normally lands me steady. On migraine-prep days, it spikes harder than usual and crashes too fast. Real talk — food is a factor here. On these days, I'm usually not pairing PFF (protein, fat, fiber). I'm grabbing something quicker and more processed than usual. I also notice it more with foods that contain soy lecithin — though honestly, that may just be because soy lecithin lives in ultra-processed foods (protein bars, packaged snacks), and those are the foods spiking me in the first place. The research on soy lecithin specifically is thin. The research on processed food and glucose chaos? Not thin at all.

2. Back-to-back swings — no stable middle

On a normal day, my glucose rises after a meal and comes back down to a steady baseline before the next one. On migraine-prep days? It never settles. Up and down every 2–4 hours, all day, never finding a stable middle. And here's a counterintuitive one: grazing on small snacks to "keep my blood sugar even" actually makes it worse for me. Each tiny snack starts another little wave. Three solid PFF meals win every time over six "healthy" little snacks.

3. By evening — it looks like a heart monitor

Here's the thing — I spent years as a heart nurse reading EKG strips. Pattern recognition is what I do. Different tool, same instinct. So when my CGM started looking like an EKG before a migraine? I paid attention.

By the time the headache shows up, I can scroll through my day on the SIGNOS app and the line looks like an EKG strip — peaks and valleys, peaks and valleys. That's the variability piece. Not one big spike. Not one bad meal. A whole day of swings my body never got a break from.

Once a heart nurse, always reading the rhythm. 🫀

What I do when I see it coming

I'm not perfect at this. Sometimes I see the pattern and the migraine still wins. But here's what I've learned to do when my graph starts looking suspicious:

• Add protein to my next meal — even if I just ate. Eggs, jerky, a protein shake. Something to anchor the next hour.

• Hydrate with electrolytes — not just water. Sodium and magnesium. Plain water alone can sometimes make things worse.

• Walk, even just 10 minutes. Movement is one of the fastest ways to flatten a glucose swing.

• Stop snacking on naked carbs. Pretzels, fruit alone, crackers, the granola bar in my purse. Those are the snacks that make the rollercoaster worse.

• Watch my stress and sleep. Cortisol drives glucose, and a bad night's sleep almost always shows up on my graph the next morning.

  
  

None of this is a cure. None of it is medical advice. It's what I do — as a nurse and a real person — when I'm reading my own data.

How I'm reading my CGM (without obsessing)

I wear the Dexcom Stelo + SIGNOS app every single day. No prescription, 14-day sensor, and the app actually translates the numbers into something useful.

It's not about getting obsessed with every number. It's about learning your patterns so you can make smarter choices in real time.

👉 Get the CGM I use here → CGM I WEAR

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Want help reading your own CGM data?

Most of you know me from my 6-week coaching rounds — those are about macros, strength training, and getting your nutrition dialed in. But CGM data is its own conversation. Most women don't need a 6-week program to figure their CGM out.

They need someone who's been there to walk them through it once.

That's why I built The CGM Conversation™ — a $77 one-on-one Zoom session where I share my honest perspective as a nurse who's worn one and lived this.

In our 30 minutes, we'll talk about:

• What it's been like wearing your CGM and the patterns you've noticed

• Eating in order, plate ratios, and the food pairings that worked for me

• If you don't have a CGM yet — which one I use and what to expect

• What's working in midlife for women like us

• A one-page Recap I'll send you after, so you don't lose what we covered

No fluff. No clinical jargon. Just the practical stuff a nurse-friend would tell you over coffee.

👉 Book The CGM Conversation™ — $77

Educational only. Not medical advice. Not designed for women on insulin or with Type 1 diabetes.

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Now I'm curious — what's YOUR pattern?

Whether you wear a CGM or not, you probably have a sense of what comes before your headaches. So I'd love to hear from you 👇

Do your headaches feel like they come after a sudden crash — that "I forgot to eat" feeling?

Or do they build after a full day of ups and downs — too much coffee, too much sugar, skipped lunch, late dinner?

Drop a comment below or DM me on Instagram @absolutelyamyable I read every single one — and the pattern recognition only gets better the more women share what they're noticing.

Health is wealth. 🤍

— Amy Alford, RN Your Glucose Nurse 

@absolutelyamyable

This blog post is for educational purposes only and reflects the personal perspective of a Registered Nurse. It is NOT medical advice and is NOT intended to diagnose, treat, cure, or prevent any condition. Always consult your licensed healthcare provider.

Affiliate disclosure: The SIGNOS link in my bio is an affiliate link. I may earn a small commission at no extra cost to you. I only share products I personally use and believe in.

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References

Nelson, C. A., Reavely, K. W., Jennings, M. R., Burger, B. J., Kim, A. C., Sant, D. W., & Bills, K. B. (2026). Glucose dysregulation and glycemic phenotyping in chronic migraine. Frontiers in Neurology, 16:1719724. doi:10.3389/fneur.2025.1719724

This content is for educational purposes only and is not medical advice. If you experience chronic migraines, please work with your healthcare provider. Always consult your provider before making changes to your diet, supplements, or care plan.