Antibiotics are important drugs. Many antibiotics can successfully treat infections caused by bacteria (bacterial infections). Antibiotics can prevent the spread of disease. And antibiotics can reduce serious disease complications.

But some antibiotics that used to be typical treatments for bacterial infections now don't work as well. And some drugs don't work at all against some bacteria. When an antibiotic no longer works against some strains of bacteria, those bacteria are said to be antibiotic resistant. Antibiotic resistance is one of the world's most urgent health problems.

The overuse and misuse of antibiotics are key factors leading to antibiotic resistance. The general public, health care providers and hospitals all can help ensure correct use of the drugs. This can lessen the growth of antibiotic resistance.

Bacteria resist a drug when the bacteria change in some way. The change may protect the bacteria from the drug's effects or limit the drug's access to the bacteria. Or the change may cause the bacteria to change the drug or destroy it.

Bacteria that survive an antibiotic treatment can multiply and pass on resistant properties. Also, some bacteria can pass on their drug-resistant properties to other bacteria. This is similar to them passing along tips to help each other survive.

The fact that bacteria develop resistance to a drug is normal and expected. But the way that drugs are used affects how quickly and to what degree resistance occurs.

The overuse of antibiotics — especially taking antibiotics when they're not the correct treatment — promotes antibiotic resistance. According to the Centers for Disease Control and Prevention, about one-third of antibiotic use in people is not needed nor appropriate.

Antibiotics treat infections caused by bacteria. But they don't treat infections caused by viruses (viral infections). For example, an antibiotic is the correct treatment for strep throat, which is caused by bacteria. But it's not the right treatment for most sore throats, which are caused by viruses.

Other common viral infections that aren't helped by the use of antibiotics include:

• Cold or runny nose
• Flu (influenza)
• Bronchitis
• Most coughs
• Some ear infections
• Some sinus infections
• Stomach flu
• Coronavirus disease 2019 (COVID-19)

Taking an antibiotic for a viral infection:

• Won't cure the infection
• Won't keep other people from getting sick
• Won't help you or your child feel better
• May cause needless and harmful side effects
• Promotes antibiotic resistance

If you take an antibiotic when you have a viral infection, the antibiotic attacks bacteria in your body. These are bacteria that are helpful or are not causing disease. This incorrect treatment can then promote antibiotic-resistant properties in harmless bacteria that can be shared with other bacteria. Or it can create an opportunity for potentially harmful bacteria to replace the harmless ones.

It's tempting to stop taking an antibiotic as soon as you feel better. But you need to take the full treatment to kill the disease-causing bacteria. If you don't take an antibiotic as prescribed, you may need to start treatment again later. If you stop taking it, it can also promote the spread of antibiotic-resistant properties among harmful bacteria.

For many years, the introduction of new antibiotics outpaced the development of antibiotic resistance. In recent years, however, the pace of drug resistance has led to a growing number of health care problems.

More than 2.8 million infections from antibiotic-resistant bacteria occur in the United States each year, resulting in 35,000 deaths.

Other results of drug-resistant infections include:

• More-serious illness
• Longer recovery
• More-frequent or longer hospital stays
• More health care provider visits
• More-expensive treatments

The proper use of antibiotics — often called antibiotic stewardship — can help:

• Keep the effectiveness of current antibiotics
• Extend the life span of current antibiotics
• Protect people from antibiotic-resistant infections
• Avoid side effects from using antibiotics incorrectly

Many hospitals and medical associations have applied new guidelines to diagnose and treat infections. These guidelines have been made to ensure effective treatments are given for bacterial infections and to reduce incorrect use of antibiotics.

The public also plays a role in antibiotic stewardship. You can help reduce the development of antibiotic resistance if you:

• Avoid pressuring your health care provider to give you an antibiotic prescription. Ask your health care provider for advice on how to treat symptoms.
• Wash your hands regularly with soap and water for at least 20 seconds. Clean any cuts or wounds to avoid bacterial infections that need antibiotic treatment.
• Get all recommended vaccines. Some vaccines protect against bacterial infections, such as diphtheria and whooping cough (pertussis). Check to see if you need any vaccines before travel, too.
• Lower your risk of getting a bacterial infection spread by food. Don't drink raw milk. Wash your hands before making food and before eating. Cook foods to a safe internal temperature.
• Use antibiotics only as prescribed by your health care provider. Take the prescribed daily amount. Complete the entire treatment. Tell your health care provider if you have any side effects.
• Never take leftover antibiotics for a later illness. They may not be the correct antibiotic. And they likely don't include a full treatment course.
• Never take antibiotics prescribed for another person or let anyone else take your antibiotics.