Drinking before and after surgery and the risk of complications

Why you are asked about your drinking habits before surgery

During the medical interview before surgery, you will be asked how often you drink and how much you drink at a time. A review from the field of anesthesia explained that drinking is common among patients having surgery and can lead to physiological changes in the body and to complications after surgery ^[4].

A 2024 review in anesthesiology and pain medicine summarized that heavy drinking and alcohol use disorder increase the risk of complications and death around the time of surgery ^[5]. It cited aspiration (breathing stomach contents into the lungs), nutritional deficiencies, blood-clotting abnormalities, seizures, and changes in blood pressure and circulation as major problems related to acute intoxication or alcohol use disorder, and explained that long-term drinking also changes how medications are broken down and how they act ^[5].

Drinking and postoperative complications: what studies found

A 2013 systematic review and meta-analysis gathered studies on drinking before surgery and complications within 30 days after surgery, and obtained figures from 55 studies ^[1]. Drinking before surgery was associated with an increased risk of complications overall (relative risk 1.56), infection (1.73), wound complications (1.23), and lung complications (1.80) ^[1]. Longer hospital stays (1.24) and admission to the intensive care unit (1.29) were also more common ^[1].

When heavy drinking was clearly defined, the risk of death after surgery was also higher, with a relative risk of 2.68 ^[1]. In contrast, light to moderate drinking did not appear to be related to complications, but very few studies included it in their analysis ^[1].

A 2026 scoping review looked at 23 studies of adults who had heart surgery or major non-cardiac surgery ^[3]. In some studies, regular drinking was associated with increases in death, intensive care unit admission, length of hospital stay, delirium, surgical site infection, and lung complications; for example, a link with surgical site infection was found in 5 of 9 studies ^[3]. However, no consistent threshold for the amount of alcohol emerged, some studies suggested a link at 2 or more drinks a day, and kidney and heart complications were not related to drinking before surgery ^[3].

Most of these studies were observational studies of patients having major surgery. None of the sources reviewed analyzed cosmetic surgery separately, so a risk of the same size is hard to apply directly.

Does stopping drinking before surgery make a difference?

A 2018 Cochrane systematic review analyzed 3 randomized controlled trials involving 140 people with hazardous drinking who drank 3 to 40 units a day ^[2]. The review defined hazardous drinking as more than 3 units a day or 21 units a week, with 1 unit equal to 12 g of ethanol ^[2].

All three studies evaluated intensive alcohol cessation programs that included medication for withdrawal symptoms, education, and relapse prevention ^[2]. Postoperative complications that needed treatment occurred in 20 of the 61 people who received a program and in 33 of the 61 who did not ^[2]. The authors considered that intensive programs aimed at complete abstinence for 4 to 8 weeks before surgery probably reduced complications, but they could not judge the effect on death rates because there was not enough data ^[2].

This evidence also has clear limitations. The number of studies and participants was small, all of the studies were conducted in Denmark, and most participants were men ^[2]. The authors stated that caution is needed in drawing firm conclusions from these results ^[2].

Cautions about stopping suddenly

A review of hospitalized orthopedic patients explained that acute alcohol withdrawal can be life-threatening, especially in patients who are forced to stop drinking because they are in the hospital ^[6]. A review from the field of anesthesia listed assessing alcohol use, supporting abstinence, adjusting the anesthesia plan to the patient's drinking history, managing pain, and monitoring for withdrawal symptoms during and after surgery as part of care around the time of surgery ^[4]. If you drink heavily, it is safer to tell your medical team in advance and make a plan together than to stop suddenly on your own.

If it is hard to stay off alcohol on your own, there are ways to get help. A 2021 scoping review of 11 studies that used text messages or smartphone apps to support lifestyle changes before and after surgery found that participant satisfaction was high, but summarized that the studies were small, which makes the effects hard to generalize ^[7].

Effects on pain control and medications

The 2024 review explained that acute or chronic drinking changes how strongly pain is felt and the pain threshold ^[5]. It said that medications used to treat alcohol use disorder, particularly naltrexone, need separate management because continuing or stopping them around the time of surgery can lead to inadequate pain control or a higher risk of relapse ^[5]. Telling your medical team accurately about your drinking habits and the medications you take allows them to plan your anesthesia and pain management appropriately.

What to tell your surgeon during your consultation

If you say you drink less than you actually do, it is difficult to assess your risk properly. Besides drinking, recovery differs from person to person depending on the extent of surgery, your health, and the medications you take, so it is best to share the following honestly.

• How often you usually drink and how much you drink at a time
• Any recent changes in how much you drink, and when you last had a drink
• Whether you have ever had withdrawal symptoms when cutting down or stopping drinking
• Other medical conditions, such as liver disease
• The medications you take, especially any medication for alcohol-related treatment