Allergic Reaction

Definition

An allergic reaction is the body's immune response to a substance that it mistakenly identifies as harmful, such as certain foods, pollen, or medications.

Scientific / Technical Definition

An allergic reaction occurs when the immune system misidentifies a normally harmless substance as a threat and releases chemicals, such as histamine, to protect the body. This response can lead to symptoms ranging from mild (such as itching or rashes) to severe (such as anaphylaxis, a life-threatening condition).

Benefits

Examples

• Consuming peanuts leading to swelling and hives
• Eating shellfish and experiencing difficulty breathing
• Pollen exposure causing hay fever symptoms

Additional Information

• effects: An allergic reaction can affect the body's respiratory system, cardiovascular system, skin, and digestive tract. Severe reactions may require immediate medical attention.

Related Terms

• Food Allergy
• Intolerance
• Histamine
• Anaphylaxis

References

• Understanding Food Allergies
• Mechanisms of Allergic Disease