• Stomach upset, which could in time lead to ulcers, pain, heartburn, nausea, vomiting, internal bleeding, or holes in the stomach or intestines

  • Stomach damage, possibly indicated by bloody, black or tarry stools or by bloody vomit

  • Facial swelling (usually indicates an allergy)

  • Asthma attack (another indicator of allergy)

  • Ringing in the ears (when taken in high doses)

  • Risk of bleeding in the brain, a medical emergency that could lead to stroke