Hypoglycemia is a medical term referring to an abnormally low level of glucose, or sugar, in the bloodstream. Glucose is the body’s primary energy source and is necessary for the proper functioning of the brain and nervous system. Alcohol consumption, especially when heavy, can severely interfere with the body’s ability to maintain healthy blood sugar levels, leading to this potentially dangerous state. Understanding the mechanism by which alcohol disrupts glucose balance is important for prevention.
How the Body Normally Regulates Blood Sugar
The liver plays a central role in maintaining a steady supply of glucose in the blood, a process known as glucose homeostasis. When food is consumed, the liver stores excess glucose as glycogen. Between meals or during fasting, the pancreas releases the hormone glucagon, signaling the liver to convert stored glycogen back into glucose and release it into the bloodstream.
Glycogen stores are limited and can be depleted after several hours of fasting, such as overnight. Once glycogen is gone, the liver switches to a backup process called gluconeogenesis, meaning “the creation of new glucose.” During this process, the liver manufactures glucose from non-carbohydrate sources like amino acids, lactate, and glycerol. This dual system ensures that the brain and other organs receive a continuous fuel supply.
Alcohol’s Interference with Glucose Production
Alcohol causes low blood sugar primarily by directly interfering with the liver’s ability to perform gluconeogenesis. When alcohol is consumed, the liver prioritizes its detoxification over all other metabolic duties. The liver uses enzymes to break down alcohol first into acetaldehyde and then into acetate.
During these metabolic steps, Nicotinamide Adenine Dinucleotide (NAD+) is converted into its reduced form, NADH. This process rapidly consumes large amounts of NAD+, causing a significant increase in the ratio of NADH to NAD+ within the liver cells. This shift in the cell’s metabolic balance, or redox state, is the core of the problem.
Gluconeogenesis requires a specific balance of NAD+/NADH to function correctly. The excess NADH generated by alcohol metabolism essentially stalls the production of new glucose by inhibiting necessary enzymes in the gluconeogenesis pathway. For example, the conversion of lactate to pyruvate, an initial step in creating new glucose, is strongly inhibited by high NADH levels.
Studies show that alcohol can decrease the rate of gluconeogenesis by up to 45% in fasting individuals. Because the liver is preoccupied with processing alcohol, it cannot create new glucose to replenish blood sugar. The body then relies solely on existing glucose, which quickly drops to dangerously low levels, resulting in hypoglycemia.
Key Factors Increasing Hypoglycemia Risk
The risk of developing alcohol-induced hypoglycemia is heightened when alcohol is consumed on an empty stomach. When a person has not eaten for several hours, the liver’s stored glycogen is already depleted. In this state, the body is entirely dependent on the inhibited process of gluconeogenesis to maintain blood sugar.
The hypoglycemic effect often develops hours after the last drink, frequently occurring during sleep. This delayed effect happens because the liver continues to metabolize alcohol for an extended period. Alcohol can also blunt the body’s natural counter-regulatory hormone response, which normally involves hormones like glucagon and adrenaline that work to raise blood sugar levels.
Individuals with diabetes are a high-risk population, especially those using insulin or certain oral diabetes medications like sulfonylureas. These medications actively lower blood sugar levels. When combined with the liver’s inability to release glucose, the combined effect can cause blood sugar to plummet, requiring careful monitoring throughout the night after alcohol consumption.
Recognizing Symptoms and Immediate Action
Symptoms of hypoglycemia can be easily confused with signs of simple intoxication, creating a danger of misdiagnosis and delayed treatment. Both conditions can cause confusion, slurred speech, drowsiness, and difficulty concentrating. Other symptoms of low blood sugar include shakiness, sweating, rapid heartbeat, and paleness.
If low blood sugar worsens, it can lead to seizures, loss of coordination, and eventually loss of consciousness. If a person has been drinking and exhibits these symptoms, it is safest to assume low blood sugar until proven otherwise. Immediate treatment involves consuming a fast-acting carbohydrate source to quickly raise blood sugar levels.
Recommended sources include fruit juice, a regular sugary soda, or glucose tablets. If the person is conscious and able to swallow, they should consume approximately 15 grams of carbohydrates and then re-check their blood sugar after 15 minutes. Emergency medical help must be sought immediately if the individual is unresponsive, unable to swallow, or if a sugary drink does not lead to recovery.