What are antibiotics?
Antibiotics damage bacteria so the body’s immune system can fight them. They do not work against viruses.
Different antibiotics work against different bacteria. Sometimes, doctors choose an antibiotic based on what they believe will work. At other times, doctors will perform tests to work out which bacteria are causing the infection, and which antibiotics are likely to be effective against them.
Many antibiotics are less effective than they once were due to bacteria becoming resistive to their effects. This is called antibiotic resistance which may be prevented by only using antibiotics if they are needed to treat a bacterial infection.
Last reviewed: November 2016