unintended, negative outcomes or consequences of a medication, treatment, procedure, or other intervention. They may be temporary or permanent, major or minor. Good reporting of adverse effects should describe their severity, how long they last, and how frequently they occur.
Synonyms: Side Effects, Harms, Negative Outcomes
Example:
A patient taking a high-dose corticosteroid experiences bone loss (osteoporosis). This is an adverse effect of long-term steroid therapy.