Understanding the Differences Between a Hangover and Withdrawal

Hangovers are an expected and extremely normal consequence of drinking too much alcohol. In fact, about “75 percent of those who drink alcohol to intoxication will experience a hangover,” causing a range of symptoms that include:

• Nausea or vomiting
• Fatigue
• Headache
• Poor sleep
• Increased light sensitivity
• Mood changes, including depression, anxiety, and irritability

Despite the fact that they are so common, hangovers are still not fully understood by scientists, and the common wisdom that hangovers are primarily caused by dehydration has been contradicted by recent research. However, most scientists believe that this phenomenon is caused by the disruption of your body’s natural balance via specific chemical processes. As Joseph Stromberg writes for Smithsonian:

The most compelling theory, at the moment, is that hangovers result from a buildup of acetaldehyde, a toxic compound, in the body. As the body processes alcohol, acetaldehyde is the very first byproduct, and it’s estimated to be between 10 and 30 times as toxic as alcohol itself.

The acetaldehyde theory could explain the appearance of hangover symptoms such as nausea, vomiting, sweating, and skin flushing. However, some researchers also posit that changes in immune function in response to alcohol consumption could be the cause of hangovers. Studies have found that high levels of cytokines—“molecules that the immune system uses for signaling”—are associated with hangover symptoms such as fatigue, nausea, headaches, and impaired cognitive function. Experts believe that cytokine release may be triggered by excessive alcohol consumption. In addition to the potential primary causes of hangovers, data reveals that secondary factors such as sleep deprivation, genetics, smoking, and health status can aggravate hangovers and significantly impact their severity.

Regardless of the exact chemical cause of hangovers, however, they are fundamentally grounded in excessive consumption. In other words, a hangover is a sign that you have had too much, and your system will return to normal once your body has cleared the alcohol.

While hangovers are caused by having too much alcohol, withdrawal is caused by having too little. In contrast to hangovers, which can affect anyone, withdrawal only happens when someone’s brain has come to depend on alcohol for normal functioning. Developing this dependency takes time, as your brain must gradually become accustomed to the continuous presence of alcohol, altering its circuitry through neuroadaptation to accommodate for this altered chemical state. Once dependency takes hold, however, your brain relies on a constant supply of alcohol to maintain neurochemical equilibrium and, over time, comes to demand ever-increasing amounts of alcohol to sustain normal activity. As WebMD explains:

Alcohol initially enhances the effect of GABA, the neurotransmitter which produces feelings of relaxation and calm. But chronic alcohol consumption eventually suppresses GABA activity so that more and more alcohol is required to produce the desired effects, a phenomenon known as tolerance. Chronic alcohol consumption also suppresses the activity of glutamate, the neurotransmitter which produces feelings of excitability. To maintain equilibrium, the glutamate system responds by functioning at a far higher level than it does in moderate drinkers and nondrinkers.

Sudden discontinuation or reduction of alcohol consumption stops this suppression of neurotransmitter activity, resulting in hyperexcitability as the brain moves into overdrive after prolonged, alcohol-induced inhibition. This can result in a host of withdrawal symptoms, including:

• Anxiety
• Agitation
• Irritability
• Tremors
• Seizures

While alcohol withdrawal symptoms can look very similar to hangover symptoms, withdrawal symptoms don’t just go away after a few hours; in fact, in the first 6-12 hours of withdrawal, minor symptoms are typically just getting started. Within 12-24 hours of stopping you may experience audio, visual, or tactile hallucinations. Within 24-48 hours you may experience seizures. Within 48-72 hours you may begin showing signs of Delirium Tremens, a psychotic condition in which you experience disturbing symptoms such as confusion, disorientation, anxiety, and tremors. These symptoms persist as your body continues to struggle to re-establish normal function over a period of days or weeks. During this time you are vulnerable to both extreme psychological and physical damage, and even possibly death.