When facing a common cold, the decision to consume alcohol can significantly influence the duration and severity of the illness. The answer to whether alcohol makes a cold worse is generally yes, and health experts strongly advise against drinking while sick. Ethanol, the alcohol found in beverages, has immediate physiological effects that intensify cold symptoms and profound biological consequences that hinder the body’s ability to fight off the virus.
Alcohol’s Direct Impact on Cold Symptoms
The most immediate physical effect of drinking alcohol while sick is the acceleration of fluid loss, which is particularly detrimental when the body is already battling a virus. Alcohol acts as a diuretic by suppressing vasopressin, a hormone that signals the kidneys to retain water. This causes the body to excrete more fluid through urination, compounding the dehydration caused by fever, sweating, and mucus production. Dehydration can then thicken mucus, making congestion feel worse, and it intensifies common cold symptoms like headaches and fatigue.
Alcohol consumption also directly aggravates respiratory symptoms, specifically nasal and sinus congestion, through vasodilation. Ethanol causes blood vessels throughout the body to expand, including those lining the nasal passages. This swelling of the nasal tissues increases stuffiness, making it harder to breathe and potentially counteracting decongestant medications. Furthermore, some alcoholic beverages, especially red wine and beer, contain histamines, which can trigger an allergy-like response, further increasing congestion and a runny nose.
A common misconception is that alcohol can help a person “sleep off” a cold, but it actually prevents the restorative rest needed for recovery. While alcohol may induce drowsiness, it fragments the sleep cycle and reduces the time spent in the Rapid Eye Movement (REM) stage. Disrupting REM sleep prevents the quality rest the body needs to support immune function. This ultimately prolongs the feeling of sickness and fatigue the next day.
The Detrimental Effect on Immune Response and Recovery
Beyond worsening symptoms, alcohol consumption imposes a systemic burden that delays the body’s ability to recover from a viral infection. The liver, a central organ for metabolism and immune regulation, is forced to prioritize processing the ethanol in the bloodstream. Because the body cannot store alcohol, the liver diverts its resources to metabolize this substance, potentially slowing down other metabolic tasks, such as clearing inflammatory byproducts or supporting the full production of immune cells.
Acute alcohol consumption can temporarily suppress the activity and function of several types of white blood cells. Specifically, alcohol can impair the ability of neutrophils and macrophages to migrate efficiently to the site of infection and engulf pathogens. Even a single episode of heavy drinking can suppress immune function for up to 24 hours, making the body less effective at fighting the invading cold virus. This reduced immune efficiency means the body struggles more to clear the virus, which can ultimately extend the duration of the cold and increase susceptibility to secondary infections.
Dangerous Interactions with Common Cold Medications
Combining alcohol with over-the-counter cold and flu preparations presents significant pharmacological risks. One of the most serious dangers involves the pain reliever acetaminophen, a common ingredient in many cold formulations. Both alcohol and acetaminophen are metabolized by the liver, and their co-consumption can overwhelm the organ’s ability to process them safely.
Chronic alcohol use or consuming alcohol while taking repeated supratherapeutic doses of acetaminophen significantly increases the risk of liver toxicity and acute liver failure. This risk is due to alcohol increasing the activity of the liver enzyme CYP2E1, which converts acetaminophen into a highly toxic byproduct called NAPQI. Simultaneously, alcohol can deplete the liver’s stores of glutathione, the substance needed to neutralize this toxin, creating a double risk for cellular damage.
Many cold medicines, especially nighttime formulas, contain antihistamines like diphenhydramine. These medications cause drowsiness, and alcohol acts as a central nervous system depressant. Mixing the two substances drastically amplifies sedation, leading to severe dizziness, impaired coordination, and poor judgment. This amplified effect increases the risk of accidents and potentially leads to profound sedation or slowed breathing.