Sugar Crash! How Low Blood Sugar Ruins Your Day

Updated: May 23, 2019

You may have heard of someone suffering from a sugar crash, and wondered what one is? Maybe you get them yourself?

I certainly know about them all too well because I used to get them several times a day when I was hooked on sugar!

In a nutshell a sugar crash is the result of eating a large amount of sugar or simple carbohydrates causing a blood sugar spike, which is then followed by a blood sugar slump.

A spike in blood sugar will give a temporary lift in energy, but that will soon be replaced by an overwhelming lethargy - or a sugar crash, which are the symptoms of low blood sugar.

As a former sugar addict, I was used to peaks and troughs throughout the day, sometimes feeling energised and then later feeling sluggish, but not really knowing what was the cause. Since quitting sugar, my energy levels are much more steady throughout the day, and sugar crashes are a thing of the past.

But in case you are suffering from occasional bouts of low blood sugar throughout your day along with the miserable feelings it can bring, I've written this blog to help you understand exactly what is happening, and how to prevent it.

woman asleep at her computer

How Our Bodies Get Their Energy

The technical term for low blood sugar is hypoglycaemia, and it can make you feel pretty horrible, as I will go into later. It happens when your blood sugar levels drop below 70 milligrams per deciliter, which is the lowest level to sustain the normal functioning of the body.

The energy source that keeps all living things going is glucose, and we get our supply of this energy source from carbohydrates, often in the form of bread, potatoes, rice, vegetables, fruit and milk. After eating, these carbs are turned into glucose which is distributed via your blood stream to every single cell in your body.

Your pancreas then creates a hormone called insulin, which takes the glucose out from your blood stream and into your cells to provide energy.

Whenever we eat sweet foods and treats, or drink sodas with sugar in them, our body takes a hit and our blood sugar rises dramatically.

No matter what type of sugar you eat, white or brown, honey, agave, maple, whatever, they all break down into roughly 50% glucose and 50% fructose when we digest them, creating unnatural spikes in our blood sugar.

Watch Out For The Simple Carbs

And it’s not just ‘sweet’ foods that will increase blood sugar levels, anything made with white processed grains such as white flour, will have the same effect. These 'simple carbohydrates' can create the same effect as eating a sweet treat because they very quickly turn to glucose and spike the levels in our blood.

sliced white bread

And unfortunately, if you spike your blood sugar, then insulin levels will overcompensate in an attempt to level out your blood, resulting this time in an unnaturally low blood sugar count.

So while eating anything that gives blood sugar levels a lift can also give you a temporary boost in energy, just remember that as soon as your insulin brings your sugar levels back down, and usually way below your normal range, then that’s when the ‘crash’ happens.

What does a blood sugar crash feel like?

A sugar crash can really make you quite unwell simply because your blood sugar levels are now too low. Remember, without enough glucose your body simply cannot operate correctly.

Every part of our body needs glucose as energy to function properly, from your muscles to your organs to your brain, and if they suddenly don’t get the energy they need then you just know you’re not going to feel good!

Symptoms of low blood sugar include:

  • Tiredness

  • Lethargy

  • Irritability

  • Headaches

  • Feeling shaky

  • Dizziness

  • Mood swings

  • Blurred vision

  • Difficulty concentrating

  • Hunger

So if you eat something with a high sugar, or high 'simple carb' content, soon enough you can expect to feel tired, lethargic and possibly irritable. You can get headaches, feel shaky, anxiety can kick in or you might have difficulty concentrating. And worse of all, low blood sugar levels will make you ‘feel’ hungry as your body becomes desperate to bring your blood sugar levels back up to normal again.