Insulin is a hormone naturally produced by the pancreas, acting as a molecular signal that allows glucose, or sugar, to enter the body’s cells for energy. Its primary function is to tightly regulate the concentration of glucose circulating in the bloodstream. Introducing extra insulin into a system that does not medically require it bypasses the body’s natural control mechanisms. This powerful hormonal influx forces blood sugar levels to drop rapidly and dangerously, initiating a medical emergency.
How Unnecessary Insulin Creates Hypoglycemia
When a person who is not experiencing high blood sugar injects insulin, the hormone immediately begins to clear glucose from the bloodstream. The exogenous insulin accelerates the uptake of glucose by fat, muscle, and liver cells. This rapid, uncontrolled transfer of glucose out of the circulation leads to a state called hypoglycemia, defined as abnormally low blood sugar.
The body’s natural defense systems attempt to counteract this sudden drop in glucose concentration. Specialized cells in the pancreas release glucagon, a counter-regulatory hormone that signals the liver to release stored glucose. This attempts to stabilize the blood sugar level.
However, the massive dose of external insulin quickly overwhelms the limited capacity of the body’s counter-regulatory hormones. The injected insulin continues to drive glucose into cells, effectively blocking the liver’s ability to raise the blood sugar back to a safe range. The resulting imbalance between the high insulin levels and the low glucose levels causes the blood sugar to continue falling, creating a profound and sustained energy deprivation in the body.
Identifying the Early Symptoms
The body responds to the falling blood sugar by activating the sympathetic nervous system, triggering a fight-or-flight response. This reaction is the first physical warning sign that the brain is being deprived of its primary fuel source. These early symptoms are categorized as adrenergic, resulting from the release of adrenaline and noradrenaline.
Adrenergic Symptoms
Individuals may experience an intense feeling of nervousness or anxiety, along with a noticeable internal tremor or shakiness. Increased perspiration, often described as cold or clammy, is common, as is a rapid, pounding heartbeat known as palpitations.
Neuroglycopenic Symptoms
As the blood glucose level drops further, the brain itself begins to suffer from a lack of fuel, leading to neuroglycopenic symptoms. These signs reflect impaired brain function and may include difficulty concentrating or a feeling of mental fog. The person might feel dizzy, lightheaded, or experience unusual tiredness and weakness.
The Progression to Severe Complications
If the early warning signs of low blood sugar are ignored and the condition is left untreated, the state of neuroglycopenia progresses to a dangerous level. The brain is uniquely dependent on a continuous supply of glucose for energy, unlike other organs which can use fats or proteins. Because the injected insulin prevents the liver from providing glucose, the brain’s energy supply is effectively cut off.
The brain cells begin to malfunction as the glucose concentration drops to extremely low levels. This profound energy crisis leads to increasing disorientation, slurred speech, and an inability to perform simple cognitive tasks. The person’s behavior may become erratic or confused, often mimicking the symptoms of severe intoxication.
The deepening glucose deprivation can eventually lead to a loss of consciousness, a state known as hypoglycemic coma. Prolonged, severe hypoglycemia can trigger seizures, which are a sign of widespread electrical disturbance in the brain. If this state of profound low blood sugar persists, the lack of fuel can cause irreversible brain damage and potentially result in death.
Immediate Emergency Response
A state of severe hypoglycemia caused by unneeded insulin is a medical emergency that requires immediate intervention. The response depends entirely on the person’s level of consciousness. For an individual who is still conscious and able to swallow safely, the immediate goal is to rapidly raise their blood sugar.
The person should immediately consume 15 to 20 grams of a fast-acting carbohydrate, such as fruit juice, soda, or glucose tablets. This simple sugar is absorbed quickly into the bloodstream, bypassing the need for digestion and counteracting the effects of the insulin. After 15 minutes, the person should recheck their blood sugar, and if it remains low, the 15-gram carbohydrate dose should be repeated.
If the person becomes unconscious or is unable to safely swallow, administering any food or liquid by mouth must be avoided due to the severe risk of choking. In this situation, emergency medical services should be called immediately. If a glucagon injection kit is available, glucagon should be administered by injection into the arm, thigh, or buttock. Glucagon is a rescue hormone that signals the liver to release its glucose stores, providing a temporary but rapid increase in blood sugar.