Too much insulin leads to hypoglycemia, or low blood sugar, when the amount of insulin exceeds the body’s immediate requirement for glucose uptake. Insulin moves glucose out of the blood and into cells for energy or storage. When this action is unopposed by sufficient circulating glucose, blood sugar levels drop below 70 milligrams per deciliter (mg/dL). The resulting lack of fuel for the brain and other organs triggers the body’s acute stress response and physical symptoms.
Recognizing the Levels of Hypoglycemia
The physical manifestations of low blood sugar are categorized based on their severity and the physiological systems affected. Mild hypoglycemia (Level 1), with blood glucose between 54 and 69 mg/dL, triggers the release of stress hormones like adrenaline. This hormonal surge causes noticeable physical signs, including a rapid heartbeat, shakiness, and excessive sweating. Hunger and a feeling of nervousness or anxiety are also common symptoms at this stage, resulting from the activation of the sympathetic nervous system.
If the blood glucose level continues to fall below 54 mg/dL, reaching Level 2 hypoglycemia, the brain begins to suffer from glucose deprivation. Symptoms shift to include issues with cognitive function and coordination, such as difficulty concentrating, slurred speech, or confusion. Individuals may exhibit unusual behavior, fatigue, or blurred vision. These signs indicate a direct threat to brain function because the central nervous system lacks sufficient energy.
The most profound drop in blood sugar results in Level 3, or severe, hypoglycemia, defined as any event requiring assistance from another person for recovery. At this stage, the individual may be unable to self-treat due to mental and physical impairment. This can manifest as a seizure, loss of consciousness, or an inability to wake up from sleep. Severe episodes require emergency intervention to prevent neurological harm.
Factors That Lead to Excess Insulin
Hypoglycemia results from an imbalance between the insulin’s effect and the body’s glucose intake or consumption. The simplest cause is accidental over-administration, such as taking an incorrect insulin dose or miscalculating the carbohydrate content of a meal. Delaying or skipping a meal after an insulin injection is a common trigger for a low sugar event, as the insulin continues to work even without the anticipated glucose from food.
Unplanned or increased physical activity can accelerate the body’s glucose use, effectively making the standard insulin dose excessive. Muscles utilize available glucose more efficiently during exercise, depleting blood sugar levels faster than expected. Furthermore, consuming alcohol inhibits the liver’s ability to release its stored glucose (glycogen) back into the bloodstream. This removes a safety mechanism against falling sugar levels and can lead to hypoglycemia hours later, especially when consumed on an empty stomach.
Emergency Response and Immediate Treatment
Immediate treatment for mild to moderate hypoglycemia involves rapidly consuming a measured amount of simple carbohydrates to elevate blood sugar levels quickly. This strategy is often referred to as the “Rule of 15.” Consume 15 grams of a fast-acting carbohydrate, such as glucose tablets, four ounces of fruit juice, or a half-can of regular soda. Foods high in fat, like chocolate, should be avoided because they slow down glucose absorption.
After consuming the carbohydrate, wait 15 minutes and then recheck the blood glucose level. If the blood sugar remains below 70 mg/dL, the 15-gram treatment step should be repeated until the level is back within a safe range. Once the blood sugar has stabilized, eating a small snack containing both protein and longer-acting carbohydrates is advised to prevent another rapid drop.
For severe hypoglycemia, where a person is disoriented, unconscious, or having a seizure, the Rule of 15 should not be attempted due to the risk of choking. In this emergency scenario, a glucagon injection or nasal spray must be administered by a trained bystander. Glucagon is a hormone that signals the liver to release its stored glucose and is the standard treatment for severe episodes. Emergency medical services should be contacted immediately, especially if the person does not regain consciousness within 15 minutes.
Strategies for Preventing Recurrence
Consistent blood glucose monitoring is key to preventing future episodes, as it allows for the early identification of downward trends. Using a continuous glucose monitor (CGM) or frequent finger-stick checks provides the necessary data to adjust insulin dosing before a low event occurs. Understanding personal glucose patterns, especially around meals and activity, is necessary for maintaining stable levels.
Properly timing insulin relative to meals is a preventative measure, as rapid-acting insulin must be matched with the timing and amount of carbohydrate intake. If physical activity increases, communicate this to a healthcare provider to discuss potential insulin dose reductions or the need for pre-exercise carbohydrate snacks. It is recommended to carry a readily available source of fast-acting glucose at all times, such as glucose tablets, and to wear medical identification that alerts others to the condition in an emergency.