Adverse effect

<p>An adverse effect is an undesired harmful effect resulting from a <a href="/facts/Pharmaceutical_drug/h9mhwWP2">medication</a> or other <a href="/facts/Surgery/fG8tWf5Y">intervention</a>, such as <a href="/facts/Surgery/fG8tWf5Y">surgery</a>. An adverse effect may be termed a "<a href="/facts/Side_effect/PhuX2haY">side effect</a>", when judged to be secondary to a main or <a href="/facts/Therapeutic_effect/hvUtqFdR">therapeutic effect</a>. The term <a href="/facts/Complication_(medicine)/uJHvzqUt">complication</a> is similar to adverse effect, but the latter is typically used in pharmacological contexts, or when the negative effect is expected or common. If the negative effect results from an unsuitable or incorrect <a href="/facts/Dose_(biochemistry)/Gez72mSn">dosage</a> or procedure, this is called a <a href="/facts/Medical_error/1RyM0bdK">medical error</a> and not an adverse effect. Adverse effects are sometimes referred to as "<a href="/facts/Iatrogenesis/GfgeWAXs">iatrogenic</a>" because they are generated by a <a href="/facts/Physician/qJ3woFvG">physician</a>/treatment. Some adverse effects occur only when starting, increasing or discontinuing a treatment. 
Using a drug or other medical intervention which is <a href="/facts/Contraindication/HawhU8x9">contraindicated</a> may increase the <a href="/facts/Risk/tbBEDA0V">risk</a> of adverse effects. Adverse effects may cause complications of a <a href="/facts/Disease/55eeQlGL">disease</a> or procedure and negatively affect its <a href="/facts/Prognosis/3DEGwPag">prognosis</a>. They may also lead to <a href="/facts/Compliance_(medicine)/cC0Wfj3H">non-compliance</a> with a treatment regimen. Adverse effects of medical treatment resulted in 142,000 deaths in 2013 up from 94,000 deaths in 1990 globally.
</p><p>The harmful outcome is usually indicated by some result such as <a href="/facts/Disease/55eeQlGL">morbidity</a>, <a href="/facts/Death/VJmq29qm">mortality</a>, alteration in <a href="/facts/Body_weight/QWW2LqSw">body weight</a>, levels of <a href="/facts/Enzyme/DSI1Fh7y">enzymes</a>, loss of function, or as a <a href="/facts/Pathology/U9b18LJG">pathological</a> change detected at the microscopic, macroscopic or physiological level. It may also be indicated by <a href="/facts/Symptom/BzP6MrTN">symptoms</a> reported by a patient. Adverse effects may cause a reversible or irreversible change, including an increase or decrease in the susceptibility of the individual to other chemicals, <a href="/facts/Food/RgNq6NAK">foods</a>, or procedures, such as <a href="/facts/Drug_interaction/T5VcSVGd">drug interactions</a>.
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Adverse effect