Understanding Low Blood Sugar: Causes, Symptoms, and Treatment

18 Sep 2025 By Meera Shah, M.B., Ch.B.

Understanding Low Blood Sugar: Causes, Symptoms, and Treatment

Low blood sugar, also known as hypoglycemia, occurs when the level of glucose (sugar) in your blood drops below what your body needs to function properly. Glucose is the primary source of energy for your body, and it's crucial for the proper functioning of the brain, muscles, and other organs. While it's most commonly associated with diabetes, hypoglycemia can also occur in people without diabetes due to various factors. Understanding the causes, recognizing the symptoms, and knowing how to treat low blood sugar are vital for maintaining overall health and preventing serious complications.

Why Low Blood Sugar Matters

Hypoglycemia can range from mild to severe. Mild cases may cause discomfort and inconvenience, while severe cases can lead to seizures, loss of consciousness, and, in rare situations, even death. For individuals with diabetes, managing blood sugar levels is an ongoing balancing act. For those without diabetes, recurrent episodes of hypoglycemia can signal underlying health issues that require investigation. Therefore, knowing about hypoglycemia empowers you to take proactive steps to manage your health effectively.

| Importance of Understanding Hypoglycemia | Explanation | | :-------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------- | | Early Detection | Recognizing the symptoms early allows for prompt treatment, preventing the condition from escalating. | | Improved Management | Understanding the causes helps in managing or avoiding factors that trigger low blood sugar levels. | | Preventing Complications | Timely intervention can prevent severe outcomes such as seizures, coma, and neurological damage. | | Enhanced Quality of Life | Effective management leads to more stable energy levels, better mood, and reduced anxiety about potential hypoglycemic episodes. | A Simple Explanation Of Insulin S Role In Blood Sugar Management

Causes of Low Blood Sugar

The causes of low blood sugar vary depending on whether you have diabetes or not. Let's explore both scenarios:

In People with Diabetes

Diabetes affects how your body regulates blood sugar. Individuals with diabetes may experience low blood sugar due to: One Simple Habit To Help Manage Blood Sugar All Day Long

Excessive Insulin or Medication: Taking too much insulin or oral diabetes medication can cause your blood sugar to drop too low.
- Example: A person mistakenly takes double their usual insulin dose.
Skipped or Delayed Meals: Not eating enough carbohydrates, or delaying or skipping meals, can deplete your glucose stores.
- Example: Forgetting to eat lunch after taking insulin in the morning.
Increased Physical Activity: Exercise increases the body's need for glucose. Without proper adjustments to medication or food intake, physical activity can lead to hypoglycemia.
- Example: Engaging in a strenuous workout without eating a snack beforehand.
Alcohol Consumption: Alcohol can interfere with the liver's ability to release glucose into the bloodstream, especially when consumed on an empty stomach.
- Example: Drinking alcohol without eating food can cause a rapid drop in blood sugar.
Kidney or Liver Problems: These conditions can affect how medications are processed in the body, leading to unexpected drops in blood sugar.
- Example: Impaired kidney function reduces the excretion of insulin, leading to an overabundance.

In People without Diabetes

Low blood sugar in individuals without diabetes, known as non-diabetic hypoglycemia, is less common but can still occur. Potential causes include:

Reactive Hypoglycemia (Postprandial Hypoglycemia): This occurs within a few hours after eating a meal, often high in carbohydrates. The body releases too much insulin in response to the meal, causing a rapid drop in blood sugar.
- Example: Experiencing shakiness and sweating shortly after eating a large bowl of pasta.
Fasting Hypoglycemia: This occurs after a prolonged period without food and is often related to an underlying medical condition.
- Example: Waking up in the middle of the night with symptoms of low blood sugar after skipping dinner.
Medications: Certain medications (not related to diabetes) can cause hypoglycemia as a side effect.
- Example: Some antibiotics, quinine (used for malaria), and salicylates (like aspirin).
Excessive Alcohol Consumption: Similar to people with diabetes, alcohol can block the release of glucose from the liver.
Critical Illness: Severe liver disease, kidney disease, advanced heart failure, and sepsis can disrupt glucose regulation.
Hormone Deficiencies: Deficiencies in certain hormones, such as cortisol (from adrenal glands) or growth hormone (from the pituitary gland), can impact blood sugar levels.
Insulinoma: A rare tumor in the pancreas that produces excess insulin.
Post-Bariatric Surgery: Patients who have undergone gastric bypass surgery may experience reactive hypoglycemia due to rapid gastric emptying and altered insulin secretion.

Recognizing the Symptoms of Low Blood Sugar

Symptoms of low blood sugar can vary from person to person and may depend on how quickly blood sugar drops. Recognizing these symptoms early is crucial for prompt treatment. Common symptoms include:

Mild to Moderate Symptoms

Shakiness or Trembling: A feeling of unsteadiness or involuntary shaking.
Sweating: Profuse sweating, often unrelated to physical activity or temperature.
Dizziness or Lightheadedness: A sensation of spinning or feeling faint.
Hunger: Intense hunger, even if you've recently eaten.
Irritability or Anxiety: Feeling agitated, nervous, or easily upset.
Confusion: Difficulty thinking clearly or concentrating.
Rapid Heartbeat: An increased heart rate or palpitations.
Blurred Vision: Temporary visual disturbances.
Weakness or Fatigue: Feeling unusually tired or lacking energy.
Headache: Persistent or throbbing headache.

Severe Symptoms

Seizures: Uncontrolled muscle contractions and loss of consciousness.
Loss of Consciousness: Passing out or becoming unresponsive.
Difficulty Speaking: Slurred speech or trouble finding words.
Incoordination: Difficulty with balance or motor control.

Symptoms in Infants and Young Children

Hypoglycemia in infants and young children can be more challenging to recognize, as they may not be able to verbalize their symptoms. Look out for:

Irritability or Crying: Unexplained fussiness or crying.
Poor Feeding: Refusal to eat or difficulty sucking.
Lethargy or Sleepiness: Unusual drowsiness or lack of alertness.
Pale or Bluish Skin: Changes in skin color.
Sweating: Unexplained sweating, especially during sleep.
Seizures: In severe cases.

Using a Blood Glucose Meter

The best way to confirm low blood sugar is to check your blood glucose level using a blood glucose meter. If your reading is below 70 mg/dL (3.9 mmol/L), you likely have hypoglycemia and need treatment. Individuals with diabetes should regularly monitor their blood sugar levels, especially if they are prone to experiencing low blood sugar.

Treating Low Blood Sugar

Prompt treatment is crucial to raise blood sugar levels and prevent severe complications. The appropriate treatment depends on the severity of the symptoms and whether the person is conscious and able to swallow.

The "15-15 Rule"

For mild to moderate hypoglycemia in someone who is conscious and able to swallow, follow the "15-15 rule":

Consume 15 Grams of Fast-Acting Carbohydrates:
- Examples:
  - 4 ounces (120 mL) of regular soda (not diet).
  - 4 ounces (120 mL) of fruit juice.
  - 1 tablespoon of honey or syrup.
  - Glucose tablets (follow package instructions for 15 grams).
  - Hard candies (5-6 pieces) that can be chewed and absorbed quickly.
Wait 15 Minutes:
- Allow the carbohydrates to raise your blood sugar level.
Check Your Blood Sugar:
- Test your blood sugar with a glucose meter.
Repeat if Necessary:
- If your blood sugar is still below 70 mg/dL (3.9 mmol/L) after 15 minutes, repeat the process until your blood sugar reaches a safe level.
Follow Up with a Meal or Snack:
- Once your blood sugar is back within the normal range, have a meal or snack containing both carbohydrates and protein to stabilize your blood sugar levels and prevent another drop.

Severe Hypoglycemia

If someone is experiencing severe symptoms (e.g., seizures, loss of consciousness) or is unable to swallow, they require immediate medical attention.

Glucagon Injection:
- If the person has been prescribed glucagon, administer it according to the instructions provided. Glucagon is a hormone that stimulates the release of glucose from the liver into the bloodstream.
- Inform family members, friends, or caregivers how to administer glucagon in case of an emergency.
Call Emergency Services (911):
- Even after a glucagon injection, it's essential to seek professional medical help.
Do Not Give Food or Drink:
- Never try to give food or drink to an unconscious person, as it could cause choking.

Hypoglycemia Unawareness

Some people with diabetes may develop hypoglycemia unawareness, meaning they no longer experience the early warning symptoms of low blood sugar. This increases the risk of severe hypoglycemia. If you have hypoglycemia unawareness:

Work with Your Healthcare Provider: To adjust your treatment plan and blood sugar targets.
Monitor Your Blood Sugar More Frequently: Use a continuous glucose monitor (CGM) or check your blood sugar more often with a traditional meter.
Educate Others: Make sure family, friends, and coworkers are aware of your condition and know how to respond if you experience severe hypoglycemia.

| Treatment Step | Action | Rationale | | :------------------------- | :----------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------- | | Mild Hypoglycemia | Consume 15g fast-acting carbs, wait 15 minutes, recheck glucose; repeat if necessary. | Rapidly raises blood sugar levels. | | Severe Hypoglycemia | Administer glucagon (if available), call emergency services. | Glucagon mobilizes stored glucose; emergency services provide critical medical care. | | Hypoglycemia Unawareness | Frequent blood glucose monitoring, adjusted treatment plan with healthcare provider, education. | Addresses the increased risk of severe hypoglycemia by maintaining tighter control and increasing awareness. |

Preventing Low Blood Sugar

Prevention is key to managing hypoglycemia, especially for people with diabetes. Here are some strategies to help prevent low blood sugar: How To Read A Blood Sugar Chart Defining Your Normal Range

For People with Diabetes

Follow Your Meal Plan:
- Eat regular meals and snacks, and avoid skipping meals.
- Consult with a registered dietitian or certified diabetes educator to create a personalized meal plan.
Monitor Blood Sugar Regularly:
- Check your blood sugar levels as directed by your healthcare provider.
- Consider using a continuous glucose monitor (CGM) for real-time tracking and alerts.
Adjust Medication Dosage:
- Work closely with your healthcare provider to adjust your insulin or oral medication dosage based on your blood sugar levels, diet, and activity level.
Be Prepared for Exercise:
- Check your blood sugar before, during, and after exercise.
- Adjust your insulin dosage or consume extra carbohydrates as needed.
Limit Alcohol Consumption:
- If you choose to drink alcohol, do so in moderation and always with food.
Carry a Source of Fast-Acting Carbohydrates:
- Keep glucose tablets, juice, or hard candies with you at all times in case your blood sugar drops.
Educate Family and Friends:
- Make sure your loved ones know the symptoms of hypoglycemia and how to administer glucagon if necessary.

For People without Diabetes

Eat Regular Meals and Snacks:
- Avoid skipping meals, and eat a balanced diet with plenty of protein, fiber, and complex carbohydrates.
Limit Sugary Foods and Drinks:
- Reduce your intake of sugary foods and drinks, which can lead to reactive hypoglycemia.
Moderate Alcohol Consumption:
- Drink alcohol in moderation and always with food.
Consult a Healthcare Provider:
- If you experience recurrent episodes of hypoglycemia, see your healthcare provider to determine the underlying cause.
Be Mindful of Medications:
- If you are taking medications known to cause hypoglycemia, be aware of the potential side effects and monitor yourself for symptoms.

| Preventive Strategy | Action | Benefit | | :------------------------- | :------------------------------------------------------------------------------------------------------ | :----------------------------------------------------------------------------------------------------------- | | Regular Meals/Snacks | Maintain consistent timing and composition of meals. | Prevents drastic fluctuations in blood glucose. | | Blood Glucose Monitoring | Frequent monitoring (especially for those with diabetes or hypoglycemia unawareness) using a glucose meter or CGM | Allows timely adjustments to medication, diet, or activity levels. | | Exercise Planning | Adjust insulin dosage/carb intake before, during, and after physical activity. | Prevents exercise-induced hypoglycemia. | | Education & Awareness | Educate self and others (family, friends) on recognizing/treating hypoglycemia, glucagon use. | Ensures rapid and appropriate intervention in case of a hypoglycemic event. | | Dietary Modifications | Reduce sugary foods, balance macronutrients. | Prevents reactive hypoglycemia by stabilizing insulin response. |

Living with Low Blood Sugar

Managing low blood sugar requires a proactive approach, especially if you have diabetes or experience recurrent episodes of hypoglycemia. Here are some additional tips for living with low blood sugar:

Create a Hypoglycemia Action Plan:
- Work with your healthcare provider to develop a detailed plan outlining how to prevent, recognize, and treat low blood sugar. Share this plan with family, friends, and caregivers.
Wear Medical Identification:
- Consider wearing a medical identification bracelet or necklace indicating that you have diabetes or are prone to hypoglycemia. This can help first responders provide appropriate care in an emergency.
Keep a Log of Hypoglycemic Episodes:
- Record the date, time, symptoms, blood sugar level, and treatment for each hypoglycemic episode. This information can help you and your healthcare provider identify patterns and adjust your treatment plan accordingly.
Learn to Recognize Your Individual Symptoms:
- Everyone experiences hypoglycemia differently. Pay attention to your body and learn to recognize your own unique symptoms.
Manage Stress:
- Stress can affect blood sugar levels. Practice relaxation techniques such as deep breathing, meditation, or yoga to manage stress.
Review Your Medications Regularly:
- Work with your healthcare provider to review all of your medications, including over-the-counter drugs and supplements, to ensure they are not contributing to hypoglycemia.
Stay Informed:
- Stay up-to-date on the latest research and treatment options for low blood sugar. Consider joining a support group for people with diabetes or hypoglycemia to connect with others and share experiences.

Understanding low blood sugar, including its causes, symptoms, and treatment options, is essential for managing your health effectively. Whether you have diabetes or experience hypoglycemia for other reasons, being proactive and informed can help you maintain stable blood sugar levels and prevent serious complications. Always consult with your healthcare provider for personalized advice and treatment recommendations.