Health Topic

Antibiotic Resistance

Antibiotics can save lives. But when they are not used properly they can become less effective. Use them only when necessary to combat antibiotic resistance.

Reviewed Reviewed by a registered pharmacistGeneral information

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Antibiotic Resistance

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.

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.

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.

Anyone can develop an antibiotic-resistant infection, but certain people may be at higher risk, including those who:

  • Have a weakened immune system from diseases such as HIV or from taking medicines that affect the immune system
  • Are getting medical care such as surgery and hospital stays
  • Take antibiotics for a long time
  • Are infants, especially if they were born prematurely
  • Are older adults

There will always be some antibiotic resistance, since it happens naturally. But you can help fight against antibiotic resistance by taking these steps:

  • Don't use antibiotics for viruses.
  • Don't pressure your health care provider to give you an antibiotic if they don't think you need one.
  • When you take antibiotics, follow the directions carefully.
  • Don't share your antibiotics with others.
  • Don't save antibiotics for later or use someone else's prescription.
  • Help prevent the spread of bacterial infections with good hygiene habits. These include washing your hands often and covering your mouth and nose when coughing or sneezing.

Centers for Disease Control and Prevention

It sits within Infections and Drug Therapy.

The lead U.S. institute for this subject is the National Institute of Allergy and Infectious Diseases.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Antibiotic Resistance

632 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Diagnosis and Tests

Treatments and Therapies

Prevention and Risk Factors

Statistics and Research

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Drug Resistance, Bacterial, Drug Resistance, Microbial. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Antibiotic Resistance, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.