by Caitlin Beale, MS, RDN May 18, 2023 3 min read

If you've ever gone too long without eating and felt irritable or had trouble concentrating, it can sometimes be a sign of low blood sugar.

When your blood sugar levels start to drop, the body responds by sending signals that it is time to eat. Cravings for more processed foods can increase as your brain tells you to find something to bring up your blood sugar (energy) levels quickly.

But before you grab that sugary snack, it's important to understand what causes low blood sugar. When you understand common signs of low blood sugar are often a signal that something is off-balance, you can listen, pay attention and start to make changes that support more balanced blood sugar levels.

What Is Blood Sugar?

All foods are broken down and absorbed into the bloodstream as sugar, also known as glucose, which is the primary fuel source for cells. However, foods with carbohydrates are the body's preferred source of glucose as they consist of sugar molecules, which are easy to digest and utilize for energy. When the body recognizes that your blood sugar is rising, it releases insulin from your pancreas, signaling to glucose receptors that it is time to move sugar out of the blood stream and into your cells. Glucose is used for immediate energy requirements — any remaining gets stored as glycogen in the liver or muscles, and when those stores are full, they are converted into fatty acids, which in excess will be stored in adipose tissue (body fat).

Conversely, when blood sugar levels drop too low, or quick energy is needed, glucagon is released by the pancreas to stimulate the release of glucose from available stores back into the bloodstream to keep blood sugar levels balanced. This process is usually tightly regulated, as your body wants to avoid extreme highs or lows in blood sugar.

If blood sugar levels drop below normal range, it can lead to a range of mild to more severe signs and symptoms which include:

  • Feeling shaky or a fast, irregular heartbeat
  • Nervousness
  • Irritability
  • Brain fog or difficulty concentrating
  • Dizziness or lightheadedness
  • Low energy and sleepiness

What Causes Low Blood Sugar?

Low blood sugar occurs when glucose levels drop below normal range. The average normal fasting glucose range is 70–100 milligrams per deciliter (mg/dL), but some people may experience symptoms of low blood sugar even at 75 mg/DL.

Certain medical conditions or medications can lead to lower blood sugar levels, but diet or lifestyle patterns are also key considerations. More processed foods or even chronic stress can keep blood sugar levels elevated, where too much insulin can be released from the pancreas. With excess insulin, blood sugar can drop quickly and below healthy levels.

Irregular meal patterns or skipping meals can also lead to lower blood sugar levels. Again, this is a physiological response where your body signals that it doesn't have the necessary fuel it requires for energy. Symptoms and feelings of hunger are typically a message to get you to eat something to balance your blood sugar levels and give your brain enough fuel to operate, as it relies on glucose to function properly.

Regulate Your Blood Sugar

Purchasing an inexpensive glucometer, you can test your own blood sugar levels first thing in the morning (fasted) and 2-3 hours after meals to understand your baseline. It's always a good idea to discuss any concerns with your health care practitioner and find the possible root cause of any imbalance, which may be contributing to low (or high) blood sugar levels.

Depending on your individual health, eating well-balanced meals that include protein and healthy fats will help to moderate spikes from carbohydrates. Favoring whole food complex carbohydrates over more refined simple carbohydrates, eating at evenly spaced intervals throughout the day and addressing lifestyle factors like sleep, exercise and stress can also help you to rebalance your body and support healthy blood sugar response.


Did you know that some people actually develop hypoglycemia (low blood sugar) from certain nutrient deficiencies, accumulated toxicities, and other health imbalances? Take a listen to this podcast to learn more about the specific underlying root causes of low blood sugar, their effects and what you can do support blood sugar balance.



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