scattered aspirin image by Roslen Mack from Fotolia.com

Although most familiar as an over-the-counter drug used for headaches and fever, aspirin can also be prescribed for the treatment of arthritic pain and swelling and for patients at risk for blood clotting-related conditions such as stroke and heart attack. Aspirin therapy has extended the life of many patients at risk for life-threatening conditions.

Effects of aspirin therapy can include greater susceptibility to bruising, though. Since it is the elderly who are most often prescribed daily aspirin as therapy, increased bruising susceptibility is a cause for concern. According to the Mayo Clinic, easy bruising is also a symptom of aging, because of aging capillaries and thinning skin. Easy bruising in response to aspirin therapy may also indicate greater problems.


Low-dose aspirin therapy refers to taking a daily minimal dose of aspirin to prevent heart attack or stroke. A daily dose of 81 mg, the same as baby aspirin, is often prescribed. Depending on the needs of the patient, though, the dosage can vary from below that to regular strength (325 mg).


As an anti-platelet drug, aspirin is a blood thinner that acts against the formation of blood clots. Platelets are the body's clotting cells, which stop bleeding by building up and forming a plug that seals the opening of a blood vessel.

Blood clots cause heart attacks and strokes when they form in arteries, blocking blood flow to the brain. The anti-platelet action of aspirin is therefore preventative of stroke and heart attack in patients who already have had a stroke or heart attack or are at high risk. Patients may be considered high risk because of their family medical history or their personal medical history or habits (e.g., diabetics, smokers, or people with high blood pressure).


The anti-clotting function of aspirin can have worse side effects than bruising. It can cause stomach bleeding and even bleeding in the brain. People with stomach ulcers, bleeding disorders, uncontrolled high blood pressure, liver or kidney disease, a history of gastrointenstinal bleeding or who are at risk of a hemorrhagic stroke (caused by bleeding in the brain rather than clotting) may not benefit from low-dose aspirin therapy.

Combination of aspirin with other medication, such as warfarin, or dietary supplements, such as fish oil, may also have dangerous effects. Consult with your doctor before using aspirin as an ongoing therapy and before you introduce other medications or supplements.

Platelet Dysfunction

Easy or spontaneous (non-injury-related) bruising in a patient using low-dose aspirin therapy can also be the result of drug-induced platelet dysfunction. You may wish to raise this possibility with your doctor.


The Mayo Clinic advises not to stop taking your medication if you have concerns about easy bruising. Surprisingly, stopping daily doses of aspirin can have a rebound effect that increases risk of heart attack or stroke because of blood clot. Instead, bring your concerns about bruising to your doctor.