Bleeds from the stomach occur throughout the general population,[see reference 1 below] and each year about one person in every thousand who is not taking aspirin experiences a stomach bleed. The risk of a bleed is greater in older people, and can be very greatly increased in people with untreated stomach trouble. [2]

Daily, low-dose aspirin (70-100 mg) increases the risk of a stomach bleed by about 70%, and this means that within a thousand people taking aspirin, one additional person will experience a stomach bleed each year [2,3]. Over time however, this additional risk of a bleed caused by aspirin appears to diminish. [4,5]

A very rare, but much more serious side effect of aspirin is a bleed into the brain. We summarise the evidence on this later in this section.

A bleed from the stomach is a crisis! Nevertheless, the evidence from a number of studies of aspirin gives some reassurance about the seriousness of the stomach bleeds caused by aspirin. [6]
First: The risk reduces over time, and after about three years of aspirin taking the evidence from trials suggests that taking aspirin poses little additional risk of a bleed.[5, 6]
Second: The likelihood of a stomach bleed is increased greatly if the stomach is diseased, that is, if there is already a stomach ulcer, or an infection of the stomach.[2] Before taking aspirin, people who have, or have had stomach trouble, and those with frequent indigestion should seek advice about whether or not they should take aspirin at all, or whether they should take a stomach protecting drug along with the aspirin. These protecting drugs can markedly reduce the risk of a stomach bleed.[7-8]
Third: The stomach bleeds caused by aspirin appear not to be as serious as spontaneous bleeds in patients not taking aspirin (9). Therefore, although a spontaneous stomach bleed occasionally leads to death, there appears to be no valid evidence that bleeds attributable to low-dose aspirin are ever fatal. Relevant evidence comes from careful overviews of trials involving tens of thousands of subjects. [see references 10-16].
Fourth: The stomach bleeds caused by aspirin are nothing as serious as the disease events prevented by aspirin – heart attacks and cancers. A numb er of very careful studies have examined this balance between the risks and the benefits of aspirin and have concluded that low-dose daily aspirin (70-100 mg daily) is highly beneficial and increases disease-free survival (17-22)
All the above was about stomach bleeds. Bleeding into the brain, causing a haemorrhagic stroke is rare, but much more serious, leading to a disabling and life-threatening stroke. Each year one or perhaps two people in every ten-thousand (10,000) people who are not taking aspirin have a cerebral bleed and experience a haemorrhagic stroke.[23] In people taking aspirin, an addition one person in every 10,000 taking aspirin may experience a haemorrhagic stroke.[23]

Raised blood pressure is a major factor in brain haemorrhage and the risk of a haemorrhagic stroke is more than doubled if there is a modest rise in blood pressure (a 20mmHg rise in systolic pressure – see reference 10). Blood pressure should therefore always be checked and if it is raised it must be treated before aspirin taking commences.

A large trial of aspirin has given some reassurance about aspirin and these cerebral bleeds. The trial was conducted in almost 20,000 patients all of whom had raised blood pressure and all of whom were receiving ‘optimal’ treatment for their hypertension. Over the next few years there was no evidence of any excess in the number of haemorrhage strokes in patients taking aspirin – 19 patients on aspirin experienced a stroke, while 20 who received no aspirin had a haemorrhagic stroke.[24].

Finally: If a bleed does occur in a person taking aspirin, the natural response is to stop taking the aspirin. The decision to stop should however be taken cautiously. Suddenly stopping aspirin risks a rebound in vascular risk, and an increase in the risk of death (25). If it is decided to stop the drug it should be withdrawn slowly, and in fact, there is evidence that even if a bleed does occur, aspirin is best continued together with a stomach protecting drug.[26]

It is most important that the balance between the benefits of a drug and the risks from that drug is carefully evaluated, and it is most important that the evaluation is not just in terms of the numbers of people who benefit and the number who are harmed by the aspirin. The ‘harms’ (bleeding) are not nearly as serious as the ‘benefits’ (reductions in vascular disease and cancer)! A number of studies have examined the balance between these and have found the balance to be highly favourable for aspirin taking by people aged about 50 and over. [17-22].

In Conclusion: : The protection of your health, and the prevention of disease, is ultimately your own responsibility and this website has been prepared to help you take an informed decision about the protection of your own health.!


  1. Lanas A, Perez-Aisa MA, Feu F et al. A nationwide study of mortality associated with hospital admission due to severe GI events and those associated with NSAID use. Amer J Gastroenterology 2005;100:1685-93.
  2. Patrono C, Garcia Rodriguez Low-dose aspirin for the prevention of atherosclerosis. New Eng J Med. 2005;353(22):2373-2383.
  3. Valkhoff VE, Sturkenboom Low-dose acetylsalicylic acid use and the risk of upper gastrointestinal bleeding: a meta-analysis of randomised clinical trials and observational studies. Can J Gastroenterol. 2013;27(3):159-167.
  4. Rodriguez GLA, Hermandez-Dias Association between aspirin and upper gastrointestinal complications: systematic review of epidemiologic studies. Br J Clin Pharmacol 2001;52:563-71.
  5. Rothwell PM, Price JF, Fowkes FGR Short-term effects of daily aspirin on cancer incidence, mortality and non-vascular death: analysis of the time course of risks and benefits in 51 randomised trials. Lancet. 2012(9826);379:1602-1612.
  6. ** Elwood and Morgan Aspirin prophylaxis: Putting gut bleeds into perspective. Editorial in Gastroenterology and Hepatology 2014;10:1-3.
  7. Lai kc., Shiu Kum Lam,Lamsoprazole for the prevention of recurrences of ulcer complications from long-term low-dose aspirin use. N Eng J Med. 2002;346(26):2033-2038.
  8. Bhatt Expert Consensus Document on reducing the gastrointestinal risks of antiplatelet therapy and NSAID use. Circulation 2008;118:1894-909.
  9. ATT Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction and stroke in high risk patients. Brit Med J 2002;324:71-86.
  10. Morgan Aspirin for the primary prevention of vascular events. Public Health 2009;123:787-8.
  11. Lanas A1, Wu P, Medin J, Mills EJ. Low doses of acetylsalicylic acid increase risk of gastrointestinal bleeding in a meta-analysis. Clinial Gastroenterol Hepatol 2011;9:762-8.
  12. McQuaid KR, Laine L. Systematic review and meta-analysis of adverse events of low-dose aspirin and clopodogrel in randomised controlled trials. Amer J med 2006;1190:624-38.
  13. Gorlick PB. Risk of haemorrhagic stroke with aspirin use: an update. Stroke 2005;36:1801-7.
  14. Hansson Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) trial. HOT study group. Lancet 1998;351:1755-62
  15. ** Wehbeh et al Aspirin has a protective effect against adverse outcomes in patients with nonvarical upper gastrointestinal bleeding. Dig Dis Sci 2015 March 3 [Epub ahead of print]
  16. Biondi-Zoccail GGL, Loyrionte Systematic review and meta-analysis on the hazards of discontinuing or not adhering to aspirin among 50,279 patients at risk for coronary artery disease. Eur Heart J. 2006;27:2667-74
  17. Sung JJ, Ching JY, Wu LC,Lee YT, Chiu PW, Leung VK et al. Continuation of low-dose aspirin therapy in peptic ulcer bleeding: a randomised trial. Ann Int Med 2010;152:1-9.
  18. Thun M, Jacobs EJ, Patrono C. The role of aspirin in cancer prevention. Nat Rev. Clin. Oncol. 2012;9(5):259-267.
  19. Pignone M, Earnshaw S, McDade Effect of including cancer mortality on the cost-effectiveness of aspirin for primary prevention in men. J Gen Intern Med May 2013 (epub ahead of print)
  20. Hassan C, Rex DK, Cooper Primary prevention of colortectal cancer with low-dose aspirin in combination with endoscopy: a cost effective analysis. Gut 2012;61:1172-9.

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