Lighting up before surgery isn’t just a bad habit — it’s a serious risk to your recovery, and one that many people underestimate. Even if you’re relatively young and in good health, smoking before an operation disrupts your body’s ability to heal. It lowers oxygen levels in your blood, damages your immune defenses and ramps up inflammation, all of which make post-surgical infections and complications far more likely.
Elective procedures like hernia repairs, joint replacements or gallbladder removals are often scheduled weeks or even months in advance. That timeline creates a powerful opportunity to intervene and reduce surgical risk. Yet many patients — and even health care systems — fail to take advantage of that window. They either delay the decision to quit smoking or assume that stopping just a few days before is enough. It isn’t.
This matters because your body doesn’t bounce back from tobacco damage overnight. The internal changes that happen when you quit — like stronger immune function, better circulation and tissue oxygenation — take time. If you cut it too close, your body goes into surgery still compromised, despite your best intentions.
In the section that follows, I’ll walk you through a 2025 study that tracked over 16,327 patients across 29 countries to find out exactly how smoking affects surgical outcomes — and what kind of quitting timeline truly protects your health.
Younger, Healthier Smokers Face Higher Surgery Risks Than They Realize
A large-scale study published in The Lancet Regional Health – Europe evaluated how cigarette smoking influences complication rates following elective abdominal surgery.1 Unlike past studies, which often focused only on current smokers or emergency surgeries, this research looked at both current and former smokers and included patients who had planned their procedures in advance.
• Researchers focused on adult patients undergoing major abdominal procedures — The study specifically looked at adults aged 18 and older who were scheduled for elective (non-emergency) abdominal surgeries, including gastrointestinal, transplant, hernia, and gynecological procedures.
About 20% of the patients were current smokers, and smoking was far more common in younger adults, men, and those without chronic conditions. In fact, the highest smoking rate — 26.8% — was seen in patients aged 18 to 40.
• Smoking was strongly linked to complications in the first 30 days after surgery — Patients who smoked had a higher risk of experiencing problems like infections, delayed healing or other medical issues in the month following surgery. Compared to people who never smoked, current smokers were 14% more likely to develop post-op complications.
Even people who had quit smoking up to a year earlier were still more likely to suffer complications than those who had never smoked. Those who quit between six weeks and one year before surgery had a 30% higher risk, while those who quit more than a year before surgery showed a 13% increased risk.
• The younger you are, the more likely you are to ignore the risks — Many people assume that smoking only harms people with heart disease or lung problems. But in this study, the people who smoked the most were often those with no chronic illnesses at all. Among patients with zero long-term conditions, 24.6% were smokers — compared to 16.6% in those with two or more chronic illnesses. The idea that young or “healthy” smokers are low risk simply isn’t true.
• Elective surgeries offer a built-in opportunity to help people quit — Because elective surgeries are scheduled weeks or months in advance, they offer a built-in runway for behavior change. If hospitals and doctors used that time to support smoking cessation — offering behavioral tools or even brain stimulation techniques — they could drastically reduce the chances of complications. But that’s not happening widely yet.
• Biological damage from smoking takes time to resolve — The paper suggests that immune system suppression from smoking plays a key role in poor healing and infection risk. Smoking alters how your white blood cells respond to injury and how your lungs clear microbes. Some immune cells don’t return to normal until six months or more after quitting.
Smoking Damages Immune Defenses and Fuels Inflammation-Driven Cancers
Before your body ever reaches the operating table, smoking has already been hard at work behind the scenes — weakening your immune defenses, disrupting healing and laying the groundwork for long-term disease. The surgical risk findings from The Lancet Regional Health – Europe align with a broader body of evidence showing that cigarettes don’t just cause acute complications.
They trigger deep, lasting changes to your immune system that increase your risk for inflammation and cancer, even after you quit.
• Cigarette smoke weakens your body’s natural defense system — According to a review published in Environmental Pollution, smoking disrupts how your immune system identifies and responds to threats.2
Your immune cells are essential for defending you against infections and cancer. But cigarette smoke, which contains over 7,000 toxic chemicals, impairs their ability to function properly. That means your body becomes less capable of recognizing and destroying harmful cells, including tumor cells.
• Long-term smoking promotes low-grade inflammation that drives disease — Inflammation is meant to be a short-term response to injury or infection. But when smoking keeps your body in a constant state of immune activation, that inflammation becomes chronic.
Over time, chronic inflammation damages healthy tissues and creates an environment where cancer cells thrive. This doesn’t just affect your lungs. Smoking-related inflammation is tied to heart disease, digestive issues, endocrine disorders and neurological decline.
• Toxic substances in cigarettes alter your biology on a cellular level — Among the most dangerous ingredients are nicotine, formaldehyde, polycyclic aromatic hydrocarbons, and heavy metals like cadmium and arsenic.
These toxins don’t just irritate your lungs — they trigger DNA damage, interfere with normal cell signaling and cause harmful changes to how your genes are expressed. These disruptions pave the way for both cancer and immune dysfunction, even years after exposure stops.
• The immune imbalance caused by smoking creates a cancer-friendly environment — The review highlights that smoking leads to what’s called an “atypical immune microenvironment,” where immune cells become too weak to eliminate abnormal cells but too active in ways that harm healthy tissue. That imbalance allows tumors to grow unchecked.
Smokers have a higher risk of lung cancer, but also bladder, pancreatic and stomach cancers — in part because of this immune disruption.
Quit Smoking Early and Rebuild Your Body’s Defense System Before Surgery
If you’re planning to have surgery, especially an elective procedure, you have a window of opportunity to protect yourself. Smoking is one of the few factors completely in your control. While it’s never too late to quit smoking, the sooner you do it, the better, whether you’re scheduled for surgery or not.
The latest research shows that your body needs more time than most people realize to heal from smoking’s effects, particularly if you’re facing surgery. Immune dysfunction, poor oxygen circulation and inflammation don’t disappear overnight. Even if you feel fine, your risk of post-op complications remains high for months after your last cigarette. That’s why it’s important to give your body the time and support it needs to repair. Here’s how I’d guide you to start preparing right now:
1. Quit smoking at least six weeks ahead of surgery, but ideally much sooner — If you’re still smoking and have an upcoming procedure, stop today. The research found that people who quit within six weeks of surgery had the highest risk of complications — even worse than current smokers.
The sweet spot for risk reduction starts after six weeks, but ideally, you want to give yourself several months. The earlier you quit, the more time your immune system and tissues have to bounce back.
2. Use the pre-surgery waiting period as a built-in reset window — Elective surgeries are scheduled ahead of time for a reason. That’s your golden opportunity to make changes. Use that runway to break nicotine dependence and boost your body’s repair mechanisms. If you’re a planner or like to be in control, think of this as a personal challenge — one that could save you from a long, painful recovery.
3. Pair movement with brain retraining to rewire your cravings — Your brain is more adaptable than you think, but you have to give it the right signals. The combination of aerobic exercise and noninvasive brain stimulation has been shown to reduce smoking urges more effectively than either therapy on its own.3
Look into safe, home-based transcranial direct current stimulation devices — some are now available to consumers. Then add regular daily movement — like brisk walking — before each session to boost your results.
4. Train your brain to interrupt craving loops with body-based tools — Cigarette cravings aren’t just habits — they’re feedback loops between your thoughts, emotions and body. Emotional Freedom Techniques (EFT), also called tapping, is one powerful way to break that loop. You could also download a mindfulness app that prompts you to take breathing breaks or guides you through stress-reduction techniques when you need them most.
These simple tools give you a way to respond differently when cravings hit, especially during emotional highs or lows.
5. Rewire your daily environment to cut ties with smoking triggers — Look at the spaces where you usually smoke. Is it your porch? Your car? The breakroom at work? Start by clearing those areas of anything connected to smoking, like ashtrays and lighters. Then change the environment. Add something new: a chair with a book, a water bottle or calming music.
This teaches your brain that those spaces now serve a different purpose — and nicotine is no longer part of it.
If you’re a younger or “healthy” smoker who’s never had surgery before, don’t let that lull you into a false sense of safety. Your risk isn’t just about your age — it’s about what’s happening under the surface. Give your body the time and support it needs to recover from years of smoke exposure. The sooner you start, the safer your surgical outcome and better your overall health will be.
FAQs About Smoking and Surgery Complications
Q: Why is quitting smoking before surgery so important?
A: Smoking weakens your immune system, lowers oxygen levels in your blood and raises your risk of surgical complications. Quitting gives your body time to repair those functions, reducing the likelihood of infections, poor wound healing and even death after surgery.
Q: How far in advance should I stop smoking before a planned surgery?
A: The most significant benefits start to appear if you quit smoking more than six weeks before surgery. The earlier you stop, the more time your body has to rebuild its defenses and improve your surgical outcome.
Q: How does smoking weaken your immune system and raise cancer risk?
A: Cigarette smoke contains over 7,000 chemicals, including toxins like nicotine, formaldehyde and heavy metals. These substances disrupt the function of key immune cells, making it harder for your body to fight infection and detect early tumor growth. Over time, this immune dysfunction fuels chronic inflammation and creates a favorable environment for cancer to develop and spread.
Q: Are there ways to make quitting more effective or easier?
A: Yes. Pairing aerobic exercise with noninvasive brain stimulation has been shown to reduce cravings more effectively than either method alone. Other tools like EFT (tapping) and mindfulness apps help retrain your brain’s response to stress and smoking cues.
Q: How can I stop myself from falling back into smoking habits?
A: Restructure your environment to avoid common triggers. Remove smoking-related items from your home and car, and change the function of areas where you used to smoke. Replacing those routines helps your brain form new associations and supports long-term change.