What is hypoglycemia? Learn about low blood sugar levels

Hypoglycemia means low blood sugar — when your blood glucose falls below the healthy normal range. Glucose is an essential fuel for your brain so blood sugar levels are very tightly regulated by your body.

For most people, low blood sugar is not usually a problem because the body can make it's own glucose in the liver to ensure that there's always enough for your brain. However, hypoglycemia can become an issue if you take medications that lower blood sugar, such as insulin or certain diabetes drugs.

What are low blood sugar levels?

Blood sugar naturally fluctuates throughout the day but is generally maintained within a narrow range. Hypoglycemia is usually defined as a blood glucose level below 3.9 mmol/L (70 mg/dL). Levels this low can cause symptoms and require immediate attention to prevent complications.

Here’s a simple guide to low blood sugar levels:

Low blood sugar symptoms

It's not uncommon for a healthy individual to have a blood sugar level between 3 and 4mmol/L while asleep. Even while awake, this blood sugar level may well not be associated with any symptoms.

However, with a blood sugar close to 3mmol/L or below, you may experience:

• Shaking or trembling
• Sweating
• Feeling anxious or irritable
• Rapid heartbeat
• Hunger
• Dizziness or lightheadedness
• Difficulty concentrating or confusion

What are the causes of low blood sugar (hypoglycemia)?

Your body can produce glucose in the liver through a process gluconeogenesis. This means that even during periods of starvation or going carbohydrate free, a healthy person would maintain a blood sugar level over 3mmol/L.

However, newborns, the elderly, people with other health problems such as diabetes can sometimes experience hypoglycemia. In these cases, the main causes of hypoglycemia include:

• Medications: Insulin or other diabetes treatments can overcome the bodies natural ability to regulate blood sugar levels leading to dangerously low blood sugar.
• Skipping meals or fasting: Not eating for a long period can reduce blood glucose.
• Excessive alcohol intake: Alcohol affects liver glucose production.
• Intense physical activity: Using up glucose without replenishing it.
• Certain medical conditions: Such as hormone deficiencies or liver/kidney problems.
• Reactive hypoglycemia: A condition where blood sugar drops after meals.

How to increase your blood sugar

If you experience low blood sugar symptoms, it’s important to raise your blood glucose quickly. Try:

• Drinking a sugary beverage like fruit juice or a regular (non-diet) soda.
• Eating quick carbs such as glucose tablets, honey or sweets.
• Snacking on fruit like bananas or grapes.
• After initial treatment, follow up with a small meal or snack containing complex carbs and protein to stabilise your levels.

How to check if you have low blood sugar levels

Unlike high blood sugar, HbA1c tests are not particularly useful for detecting low blood sugar because they reflect average glucose over 2-3 months and don’t capture brief or occasional hypoglycemic episodes.

The best way to monitor for low blood sugar is with a continuous glucose monitor (CGM) — a small wearable device that tracks your glucose levels throughout the day in real time. This technology helps detect sudden drops and patterns that may require medical attention.

At Selph, we offer a CGM programme that provides detailed glucose insights and a consultation with one of metabolic health experts, helping you manage and understand your blood sugar fluctuations better.