Based on NIH | Does smoking increase the risk of stomach bleeding when taking aspirin?

Yes smoking can increase the risk of stomach (gastrointestinal) bleeding when you take aspirin, and the risk tends to be higher when other factors are present such as older age, prior ulcers, alcohol use, or use of certain other medicines. ^{[1] [2]}

Why aspirin can cause stomach bleeding

Aspirin is a nonsteroidal anti‑inflammatory drug (NSAID) that can irritate the stomach lining and reduce protective prostaglandins, which can lead to ulcers and bleeding, even at low doses. This bleeding risk is well recognized for aspirin and other NSAIDs. ^{[3] [4]}

How smoking adds to the risk

Multiple official drug safety documents list smoking as a factor that increases the chance of NSAID‑related gastrointestinal bleeding. Smoking appears to compound the mucosal injury and impair healing, which can make aspirin‑related bleeding more likely. ^{[1] [5]} In these safety communications, smoking is grouped with other amplifying risks such as alcohol use, longer duration of NSAID therapy, older age, and poor overall health. ^{[1] [2]}

Other common risk factors to consider

• Prior peptic ulcer or GI bleeding: dramatically increases risk when using NSAIDs. ^[1]
• Concomitant medicines: oral corticosteroids, anticoagulants (blood thinners), SSRIs/SNRIs, or other NSAIDs. These combinations can raise bleeding risk considerably. ^{[1] [5]}
• Higher dose or longer use: risk rises with dose and duration. ^[5]
• Alcohol use and older age: both add to bleeding risk. ^{[2] [5]}

Practical steps to lower your risk

• Use the lowest effective dose for the shortest possible time if aspirin is being taken for pain/fever. This general NSAID precaution is advised to minimize GI harm. ^[5]
• If aspirin is needed for heart protection (low‑dose aspirin), discuss individualized protection: clinicians often consider stomach‑protective therapy (proton pump inhibitors, PPIs) for people at higher risk. High‑risk features include prior ulcers/bleeding, older age, or interacting medications. ^[4]
• Avoid combining aspirin with other NSAIDs and limit alcohol, as both raise bleeding risk. ^{[6] [7]}
• Address smoking: quitting can reduce several GI and cardiovascular risks over time. Because smoking is a recognized risk amplifier for NSAID‑related bleeding, cessation is a meaningful preventive step. ^{[1] [5]}

What the evidence shows

• Case‑control and pharmacoepidemiologic data show that aspirin use is linked with substantially higher odds of major upper GI bleeding, even with intermittent use. This establishes aspirin as a clear contributor to GI bleeding risk. ^[3]
• Reviews of low‑dose aspirin consistently identify classic GI risk factors, and clinical practice commonly applies NSAID risk factors including smoking to aspirin users. In higher‑risk users, PPIs are often recommended to reduce GI complications. ^[4]

Quick reference table

Factor	Effect on GI bleeding risk with aspirin
Smoking	Increases risk as a recognized NSAID risk amplifier. [1] [5]
Prior ulcer or GI bleed	Greatly increases risk; strongest predictor. [1]
Alcohol use	Increases risk, especially with regular intake. [2] [5]
Concomitant meds (steroids, anticoagulants, SSRIs/SNRIs, other NSAIDs)	Increases risk due to additive effects on bleeding and mucosal injury. [1] [5]
Higher dose/longer duration	Increases risk cumulatively. [5]
Older age/poor health	Increases risk and severity of events. [2] [5]

Bottom line

Smoking is one of several factors that can raise the chance of stomach bleeding when taking aspirin. If you smoke and need aspirin especially long term talk with your clinician about ways to lower your risk, such as stopping smoking, avoiding alcohol, minimizing dose/duration, reviewing interacting medicines, and considering a PPI if your overall risk is high. ^{[1] [5] [4]}