Aspirin is a common over-the-counter medication used for treating fever, pain and inflammation (redness and swelling). However, aspirin is not recommended for children under 12 years of age.
Over-the-counter (OTC) pain relievers can be very effective for headaches in adults. Most of these are safe for children, as well. However, aspirin is an important exception. Aspirin is associated with a risk of Reye's syndrome in children.
Reye syndrome is a rare condition where children develop liver disease and encephalopathy following viral illness, usually in combination with the ingestion of aspirin.
Children under 16, haemophiliacs and anyone taking blood thinners already should not take it. It should be avoided in anyone with an ulcer. Those with asthma, kidney problems or gout should be cautious about using it.