Hypoglycaemia is a condition characterised by abnormally low blood glucose (sugar) levels, typically below 70 milligrams (about twice the weight of a grain of rice) per decilitre (mg/dL). It occurs when there's an imbalance between the body's glucose supply and its utilisation. While glucose is the primary fuel for the body's cells, especially the brain, hypoglycaemia disrupts this crucial energy source.

This condition is most associated with diabetes treatment, particularly in individuals using insulin or certain oral medications. If left untreated, severe hypoglycaemia can lead to serious complications, including loss of consciousness, seizures, and in extreme cases, death. Recognising the signs of hypoglycaemia and understanding its causes are essential for prompt treatment and prevention and this article explains it all.

Causes of Hypoglycaemia

Hypoglycaemia can stem from several causes, including:

Not eating enough: Skipping meals or going too long without eating can lead to low blood sugar levels.
Increased physical activity: Engaging in strenuous exercise without consuming sufficient carbohydrates can cause hypoglycaemia.
Certain medications: Medications such as sulfonylureas, meglitinides, and insulin can lower blood sugar levels.
Alcohol consumption: Drinking alcohol without eating can cause hypoglycaemia.
Liver diseases: Certain liver conditions, such as liver cirrhosis, can lead to hypoglycaemia.
Insulinoma: A rare condition where the pancreas produces too much insulin, causing low blood sugar levels.
Endocrine problems: Hormonal imbalances, such as Cushing's syndrome, can cause hypoglycaemia.
Reactive hypoglycaemia: A condition where blood sugar levels drop several hours after eating a meal.
Tumours: Certain tumours, such as insulinomas, can cause hypoglycaemia.

Symptoms of Hypoglycaemia

Mild hypoglycaemia may present with symptoms such as:

Early warning signs and symptoms:
Looking pale (pallor)
Shakiness
Dizziness or lightheadedness
Sweating
Hunger or nausea
An irregular or fast heartbeat
Difficulty concentrating
Feeling weak and having no energy (fatigue)
Irritability or anxiety
Headache
Tingling or numbness of the lips, tongue, or cheek

1. Nighttime signs and symptoms:

Damp sheets or nightclothes due to perspiration
Nightmares
Tiredness, irritability, or confusion upon waking

2. Severe signs and symptoms:

Confusion, unusual behaviour, or both
Loss of coordination
Difficulty speaking or slurred speech
Blurry or tunnel vision
Inability to eat or drink
Muscle weakness
Drowsiness
Convulsions or seizures
Unconsciousness
Death, rarely

Diagnosis of Hypoglycaemia

Diagnosing hypoglycaemia involves a combination of clinical evaluation, laboratory tests, and imaging studies. Here are the key points on the diagnosis of hypoglycaemia:

1. Clinical Evaluation

Physical Exam: A physical exam is conducted to assess the patient's overall health and identify any signs of hypoglycaemia, such as pale skin, shakiness, or confusion.
Medical History: The patient's medical history is reviewed to identify any underlying conditions that could be contributing to hypoglycaemia.

2. Laboratory Tests

Blood Glucose Level: The most reliable method of diagnosing hypoglycaemia is through identifying Whipple's triad, which includes a blood sugar level below 70 mg/dL (3.9 mmol/L), symptoms related to low blood sugar, and improvement of symptoms when blood sugar is restored to normal.

Insulin Level: Insulin levels are measured to determine if the hypoglycaemia is caused by insulin or another medication.
C-peptide Level: C-peptide levels are measured to distinguish endogenous from exogenous hypoglycaemia.
Proinsulin Level: Proinsulin levels are measured to determine if the hypoglycaemia is caused by an insulinoma.
Beta-hydroxybutyrate Level: Beta-hydroxybutyrate levels are measured to detect the presence of ketones, which can indicate a metabolic disorder.
Oral Hypoglycaemic Agent Screen: This test is used to detect the presence of oral hypoglycaemic agents in the blood.
Response to Glucagon: The patient's response to glucagon injection is monitored to determine if the hypoglycaemia is caused by an insulinoma.

Treatment of Hypoglycaemia

Treatment for Hypoglycaemia varies from mild to severe range:

Treatment for Mild to Moderate Hypoglycaemia
The mainstay of treatment is consuming carbohydrates or glucose to raise blood sugar levels quickly.
The recommended approach is the "15-15 rule": consume 15-20 grams of carbohydrates, then recheck blood sugar in 15 minutes. Repeat until blood sugar is above 70 mg/dL.

Preferred treatments include:

Glucose tablets or gels
4-6 pieces of hard candy or jellybeans
1 tbsp of sugar, corn syrup, or honey

Treatment for Severe Hypoglycaemia

For unconscious or unresponsive patients, glucagon injection is the preferred treatment.
Intravenous (IV) dextrose is also effective for raising blood sugar levels quickly in severe cases.
Glucagon is more costly and can cause nausea/vomiting, so IV dextrose is preferred if the patient has IV access.

Prevention of Hypoglycaemia

Carbohydrate Intake: Patients should be instructed on the importance of giving insulin with appropriate dosage and timing in relation to meals.
Meal Planning: Patients should be given a personalised meal plan that includes the amount of carbohydrates in meals and its effect on blood glucose concentration.
Bedtime Snack: Patients at risk of nocturnal hypoglycaemia should be instructed to take a bedtime snack to prevent overnight hypoglycaemia.
Physical Exercise: Patients should be advised to exercise safely and avoid physical exertion when blood sugar levels are low.
Monitoring Blood Sugar: Patients should be instructed to monitor their blood sugar levels before and after exercise to avoid hypoglycaemia.

Preventing hypoglycaemia requires a comprehensive approach that includes patient education, dietary and exercise regimens, glucose monitoring, medication adjustment, and close clinical supervision. By following these tips, patients with diabetes can reduce their risk of hypoglycaemia and maintain optimal glycaemic control.