Hypoglycaemia or Insulin Resistance? How to Tell What's Really Going On

In my last post, I walked through how beautifully your body regulates blood sugar when everything is working as it should. Today I want to talk about what happens when that system starts to wobble, because dysglycaemia, the umbrella term for blood sugar that's running too low, too high, or swinging wildly between the two, shows up far more often than people realise. And it rarely announces itself as a blood sugar problem.

The question I ask almost every client now is simple: how do you feel after you eat?

That one answer tells me an enormous amount.

Two very different pictures

Running too low (hypoglycaemia)

If you feel noticeably better after eating, if your energy lifts, your mood steadies, your anxiety eases, that's a clue you're spending a lot of your day running on too little glucose. The classic pattern looks like this: fatigue between meals, a hard crash around 3 or 4pm, sugar cravings in the afternoon and after dinner, shakiness or anxiety if a meal is delayed, brain fog, waking in the night and struggling to get back to sleep, headaches, irritability, and weight that's stubbornly hard to shift.

Importantly, this pattern is usually not a pancreas problem. It's a nervous system problem. Skipped meals, long fasting windows, not enough protein or fibre, high caffeine intake to suppress appetite, and chronic overtraining all push you into this pattern.

Here's the mechanism worth understanding: when glucose drops too low, your adrenal glands release adrenaline first, followed about twenty minutes later by cortisol. Both of these stress hormones push your liver to release more glucose. So if you've gone too long without eating, particularly overnight, you can find yourself wide awake at 2 or 3am, not because of stress in the abstract sense, but because your body has run out of stored glycogen and is using stress hormones to manufacture an emergency glucose supply. Your nervous system and your blood sugar are far more linked than most people realise.

Running too high (insulin resistance)

This picture looks almost the opposite. If you feel worse after eating, more tired, foggier, craving something sweet shortly after a meal, that points towards insulin resistance, where glucose is struggling to get into your cells despite there being plenty of insulin around to escort it in.

The pattern here tends to include fatigue after meals rather than between them, brain fog that follows eating, sugar cravings post meal, low-grade inflammation through the day, needing the loo frequently, and finding exercise hard going, though usually feeling noticeably better afterwards. That last point is a useful clue. When glucose can't get into your cells properly, your mitochondria, the energy factories inside every cell, are starved of fuel even though there's glucose floating around in your blood. No wonder you're tired. Your body is, quite literally, sitting next to a fuel tank it can't access.

The vicious cycles worth understanding

What makes insulin resistance particularly stubborn is that it doesn't sit still. It feeds several self-reinforcing loops.

The first is inflammatory. High circulating glucose that isn't getting into cells starts binding to proteins and fats instead, forming what are called advanced glycation end products, essentially the biological equivalent of caramelising from the inside. These trigger inflammatory receptors called RAGE, which generate more inflammation, which worsens insulin resistance further. It's a genuine loop, and it's also why chronic low-grade inflammation and dysglycaemia so often travel together.

The second is hormonal, and this is the piece I think deserves far more attention than it gets. Insulin resistance upregulates an enzyme called aromatase, which converts androgens into oestrogen. The result is higher circulating oestrogen, and this single mechanism can show up as hormonal acne, heavier or more painful periods, and is a recognised contributor in conditions like endometriosis, where local oestrogen and inflammation feed each other in a similar loop. If you've been treating acne or painful periods purely as a skin or reproductive issue without ever looking at blood sugar, this is often the missing piece.

The third loop involves your fat cells directly. As fat cells become more burdened, they release more leptin, the hormone responsible for telling your brain you're full. Over time this leads to leptin resistance, where your brain stops listening to that signal altogether, even though leptin levels are high. The result is a frustrating cycle of continual hunger and overeating that has nothing to do with willpower and everything to do with a hormonal signal that's no longer being heard.

Why this rarely gets caught

Standard blood tests very often come back completely normal in early dysglycaemia, which is part of why it goes unrecognised for so long. A fasting glucose alone doesn't tell the whole story, particularly in the hypoglycaemic pattern, where the issue is more about the swings and the nervous system response than a single static number.

A couple of physical clues I look for in clinic: feeling cold before meals, and blood pressure that runs on the low side, can both point towards a hypoglycaemic pattern worth investigating further.

What this isn't about

I want to be clear that dysglycaemia isn't only something that shows up in people who are overweight. It can present in someone lean and outwardly healthy just as easily as in someone carrying extra weight. The symptoms are so varied, fatigue, mood, skin, sleep, fertility, joint pain, that it's genuinely one of the most under-recognised root causes I see, hiding behind a dozen different presenting complaints.

In my next post, I'll walk through the testing that actually picks this up, the markers worth asking your GP or practitioner for, and the practical steps that make the biggest difference in rebalancing this system.

If any of this sounds familiar, book a consultation here and we can dig into what your body is actually telling you.