Antibiotic Resistance

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/9/2026Status: primary verified

What are antibiotics? Antibiotics are medicines that treat bacterial infections in humans and animals. They work by killing the bacteria or making it hard for the bacteria to grow and multiply. When used properly, antibiotics can save lives. But there is a growing problem of antibiotic resistance. What is antibiotic resistance? Antibiotic resistance happens when bacteria change and can resist the effects of an antibiotic. The bacteria are not killed, and they continue to grow. The infections these bacteria cause are called resistant infections. Resistant infections can be difficult, and sometimes impossible, to treat. In some cases, they can even be deadly. Antibiotic resistance does not mean that your body is resistant to antibiotics. There are many different types of resistant infections. They include MRSA and drug-resistant tuberculosis (TB). If you get a resistant infection, you might need: A long hospital stay A long recovery Follow-up visits with health care providers Treatments that are expensive and may have severe side effects Antibiotic resistance is one type of antimicrobial resistance. There are other types; viruses , fungi , and parasites can also become resistant to medicines. How do bacteria become resistant to antibiotics? Antibiotic resistance is a natural process that happens over time. To survive, bacteria can develop defense strategies against antibiotics. This happens through genetic changes in the bacteria. These resistant bacteria survive, grow, and spread. Each time you take antibiotics, there is a risk that the bacteria will become resistant. So it is important to only take antibiotics when you really need them. They won't work on viral infections such as colds and the flu . And you don't need antibiotics for every bacterial infection. For example, you may not need them for some sinus and ear infections. Who is more likely to develop an antibiotic-resistant infection? Anyone can develop an antibiotic-resistant infection, but certain people m

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This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.