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Regular Aspirin Side Effects: What to Know

Last reviewed: December 2025

Overview

Regular-strength aspirin, like all NSAIDs, carries risks of side effects, particularly with long-term or high-dose use. The most significant concerns involve the gastrointestinal tract and bleeding. Understanding these risks helps with safe use.

Common Side Effects

Gastrointestinal:

  • Stomach upset or pain
  • Heartburn
  • Nausea
  • Indigestion

Other common effects:

  • Easy bruising
  • Prolonged bleeding from cuts
  • Ringing in ears (with higher doses)

Serious Side Effects

Gastrointestinal Bleeding

This is the most significant risk with regular aspirin use:

  • Stomach ulcers — can occur without warning
  • GI bleeding — may be silent until severe
  • Perforation — rare but serious
  • Risk increases with: age, history of ulcers, alcohol, other NSAIDs, corticosteroids

Warning signs:

  • Black, tarry stools
  • Vomiting blood or material like coffee grounds
  • Severe stomach pain
  • Weakness or dizziness

Allergic Reactions

Aspirin sensitivity:

  • Can cause severe asthma attacks
  • Hives or skin reactions
  • Swelling of face, lips, tongue
  • Anaphylaxis (rare but serious)

Aspirin-exacerbated respiratory disease (AERD):

  • Triad of asthma, nasal polyps, aspirin sensitivity
  • Affects about 7% of adults with asthma
  • Can trigger severe respiratory symptoms

Reye’s Syndrome

Critical warning for children:

  • Life-threatening condition affecting liver and brain
  • Associated with aspirin use during viral illness
  • NEVER give aspirin to children under 18 with fever
  • Includes flu, chickenpox, and other viral infections

Bleeding Complications

  • Hemorrhagic stroke (rare)
  • Excessive bleeding from injuries or surgery
  • Prolonged bleeding time

Tinnitus (Ringing in Ears)

  • Often a sign of too much aspirin
  • Usually reversible when dose reduced
  • Can indicate aspirin toxicity
  • Seek medical attention if persistent

Aspirin Toxicity (Overdose)

  • Rapid breathing
  • Confusion
  • High fever
  • Ringing in ears
  • Nausea and vomiting
  • Requires immediate medical attention

Long-Term Use Concerns

With chronic use:

  • Increased GI bleeding risk
  • Possible kidney effects
  • Iron deficiency anemia (from chronic GI blood loss)
  • Drug interactions more likely

Who Is at Higher Risk

Factors increasing side effect risk:

  • Age over 60
  • History of ulcers or GI bleeding
  • Use of alcohol
  • Use of other NSAIDs or corticosteroids
  • Blood clotting disorders
  • Kidney or liver disease

Reducing Side Effects

Strategies that may help:

  • Take with food
  • Use the lowest effective dose
  • Use for shortest time needed
  • Avoid alcohol
  • Stay hydrated
  • Consider buffered or enteric-coated forms (though bleeding risk remains)

When to Stop and Seek Help

Stop aspirin and get medical attention for:

  • Signs of GI bleeding (black stools, vomiting blood)
  • Allergic reaction symptoms
  • Severe stomach pain
  • Ringing in ears that doesn’t stop
  • Signs of overdose
  • Unusual bruising or bleeding

Comparison to Other Pain Relievers

Versus acetaminophen:

  • Aspirin: GI and bleeding risks, but anti-inflammatory
  • Acetaminophen: Liver risk, no anti-inflammatory effect

Versus ibuprofen:

  • Similar GI risks
  • Aspirin’s antiplatelet effect is irreversible
  • Ibuprofen’s effect is reversible

Sources

  • FDA — Aspirin Safety Information
  • MedlinePlus — Aspirin Side Effects
  • American Academy of Pediatrics — Reye’s Syndrome
  • UpToDate — Aspirin: Adverse Effects
Last reviewed: December 2025