When teaching a client about a new drug that has been prescribed, the client asks the nurse to explain the difference between a side effect and an adverse reaction. Which response by the nurse is correct?

A. "Side effects are severe, and adverse reactions are mild.": This is incorrect because side effects are generally expected, predictable, and usually mild, such as drowsiness or mild nausea. Severe effects are categorized as adverse reactions, not side effects. B. "Both side effects and adverse reactions are severe.": This is incorrect because not all medication effects are severe. Side effects are typically mild and manageable, whereas adverse reactions are unexpected, harmful, and often severe. C. "Side effects are mild, and adverse effects are severe.": Side effects are predictable, often dose-related responses to a medication, such as dry mouth or mild dizziness, and usually do not require discontinuing the drug. Adverse reactions are harmful, unintended, and potentially life-threatening effects that may necessitate stopping the medication and providing medical intervention, such as anaphylaxis or hepatotoxicity. D. "Both side effects and adverse reactions are mild.": This is incorrect because adverse reactions can be severe or life-threatening, whereas side effects are usually mild. Treating both as mild would underestimate the risk associated with adverse reactions.