About Flu

Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as older people, young children, and people with certain health conditions, are at higher risk of serious flu complications.  There are two main types of influenza (flu) viruses: Types A and B. The influenza A and B viruses that routinely spread in people (human influenza viruses) are responsible for seasonal flu epidemics each year.

The best way to reduce the risk of flu and its potentially serious complications is by getting vaccinated each year.

Preventive Steps

Take time to get a flu vaccine.

  • CDC recommends a yearly flu vaccine as the first and most important step in protecting against flu viruses.
  • Flu vaccines help to reduce the burden of flu illnesses, hospitalizations and deaths on the health care system each year. (Read more about flu vaccine benefits.)
  • This season, all flu vaccines will be designed to protect against the four flu viruses that research indicates will be most common. (Visit Vaccine Virus Selection for this season’s vaccine composition.)
  • Everyone 6 months and older should get an annual flu vaccine, ideally by the end of October. Learn more about vaccine timing.
  • Vaccination of people at higher risk of developing serious flu complications is especially important to decrease their risk of severe flu illness.
  • People at higher risk of serious flu complications include young children, pregnant people, people with certain chronic health conditions like asthma, diabetes or heart and lung disease, and people 65 years and older.
  • Vaccination also is important for health care workers, and other people who live with or care for people at higher risk to keep from spreading flu to them. This is especially true for people who work in long-term care facilities, which are home to many of the people most vulnerable to flu.
  • Children younger than 6 months are at higher risk of serious flu illness but are too young to be vaccinated. People who care for infants should be vaccinated instead.

Take everyday preventive actions to stop the spread of germs.

  • Take everyday preventive actions that are recommended to reduce the spread of flu.
    • Avoid close contact with people who are sick.
    • If you are sick, limit contact with others as much as possible to keep from infecting them.
  • Cover coughs and sneezes.
    • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.
  • Avoid touching your eyes, nose, and mouth. Germs spread this way.
  • Clean and disinfect surfaces and objects that may be contaminated with viruses that cause flu.
  • For flu, CDC recommends that people stay home for at least 24 hours after their fever is gone except to get medical care or other necessities. Fever should be gone without the need to use a fever-reducing medicine. Note that the stay-at-home guidance for COVID-19 may be different. Learn about some of the similarities and differences between flu and COVID-19.
  • In the context of the COVID-19 pandemic, local governments or public health departments may recommend additional precautions be taken in your community. Follow those instructions.

Take flu antiviral drugs if your doctor prescribes them.

  • If you are sick with flu, antiviral drugs can be used to treat your illness.
  • Antiviral drugs are different from antibiotics. They are prescription medicines (pills, liquid or an inhaled powder) and are not available over-the-counter.
  • Antiviral drugs can make flu illness milder and shorten the time you are sick. They may also prevent serious flu complications. For people with higher risk factors [308 KB, 2 Pages], treatment with an antiviral drug can mean the difference between having a milder illness versus a very serious illness that could result in a hospital stay.
  • Studies show that flu antiviral drugs work best for treatment when they are started within 2 days of getting sick, but starting them later can still be helpful, especially if the sick person has a higher risk factor or is very sick from flu.
  • If you are at higher risk from flu and get flu symptoms, call your health care provider early so you can be treated with flu antivirals if needed. Follow your doctor’s instructions for taking this drug.

Flu symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Some people also may have vomiting and diarrhea. People may be infected with flu and have respiratory symptoms without a fever. Visit CDC’s website to find out what to do if you get sick with flu. Learn about some of the similarities and differences between flu and COVID-19, and the difference between flu and the common cold.

Planning for Pregnancy

Pregnant? Don’t Smoke!

Smoking during pregnancy can cause babies to be born too small or too early (preterm birth), certain birth defects, and stillbirth. Quitting smoking can be hard, but it is one of the best ways a woman can protect herself and her developing baby. For free help, call 1-800-QUIT-NOW (1-800-784-8669).

Many people know that smoking causes cancer, heart disease, and stroke. But women who smoke during pregnancy put themselves and their developing babies at risk for other health problems. Even being around tobacco smoke puts a woman and her developing baby at risk for health problems.

Smoking during Pregnancy Affects Your Developing Baby’s Health

Smoking during pregnancy can cause babies to be born too small or too early. Women who smoke during pregnancy are more likely to have a baby with a birth defect of the mouth and lip called an orofacial cleft.

Babies who breathe in other people’s tobacco smoke are more likely to have ear infections and lung infections, like bronchitis and pneumonia; if they have asthma, breathing in other people’s tobacco smoke can trigger asthma attacks. These babies are also more likely to die from Sudden Infant Death Syndrome (SIDS), a sudden and unexpected infant death that has no immediately obvious cause after investigation.

It Is Never “Too Late” to Quit Smoking During Pregnancy!

Quitting smoking before getting pregnant is best. But for women who are already pregnant, quitting as early as possible can still help protect against some health problems for their developing babies, such as being born too small or too early. It is never too late to quit smoking.

It is important to quit smoking for good. A women might think it is safe to start smoking again after her baby is born. But babies of mothers who smoke may breathe in the secondhand tobacco smoke that can harm their health. Although quitting for good can be hard, the benefits are worth it—a healthy baby and many more years of good health to enjoy with him or her.

If you or someone you know wants to quit smoking, talk to your healthcare provider about strategies. For support in quitting, including free quit coaching, a free quit plan, free educational materials, and referrals to local resources, please call 1-800-QUIT-NOW (1-800-784-8669); TTY 1-800-332-8615.

Planning for Pregnancy

If you are trying to have a baby or are just thinking about it, it is not too early to start getting ready for pregnancy. Preconception health and health care focus on things you can do before and between pregnancies to increase the chances of having a healthy baby. For some women, getting their body ready for pregnancy takes a few months. For other women, it might take longer. Whether this is your first, second, or sixth baby, the following are important steps to help you get ready for the healthiest pregnancy possible.

1. Make a Plan and Take Action

Whether or not you’ve written them down, you’ve probably thought about your goals for having or not having children, and how to achieve those goals. For example, when you didn’t want to have a baby, you used effective birth control methods to achieve your goals. Now that you’re thinking about getting pregnant, it’s really important to take steps to achieve your goal [PDF – 764 KB]—getting pregnant and having a healthy baby!

2. See Your Doctor

Before getting pregnant, talk to your doctor about preconception health care. Your doctor will want to discuss your health history and any medical conditions you currently have that could affect a pregnancy. He or she also will discuss any previous pregnancy problems, medicines that you currently are taking, vaccinations that you might need, and steps you can take before pregnancy to prevent certain birth defects.

If your doctor has not talked with you about this type of care―ask about it! Take a list of talking points so you don’t forget anything!

Be sure to talk to your doctor about:

Medical Conditions

If you currently have any medical conditions, be sure they are under control and being treated. Some of these conditions include: sexually transmitted diseases (STDs), diabetes, thyroid disease, high blood pressure, and other chronic diseases.

Lifestyle and Behaviors

Talk with your doctor or another health professional if you smoke, drink alcohol, or use certain drugs; live in a stressful or abusive environment; or work with or live around toxic substances. Health care professionals can help you with counseling, treatment, and other support services.

Medications

Taking certain medicines during pregnancy can cause serious birth defects. These include some prescription and over-the-counter medications and dietary or herbal supplements. If you are planning a pregnancy, you should discuss the need for any medication with your doctor before becoming pregnant and make sure you are taking only those medications that are necessary.

People may use opioids as prescribed, may misuse prescription opioids, may use illicit opioids such as heroin, or may use opioids as part of medication-assisted treatment for opioid use disorder. If a woman is pregnant or planning to become pregnant, the first thing she should do is talk to a healthcare provider. Some women need to take an opioid medication during pregnancy to manage pain or to treat opioid use disorder. Creating a treatment plan for opioid use disorder, as well as other co-occurring health conditions, before pregnancy can help a woman increase her chances of a healthy pregnancy. If you are struggling with an opioid use disorder, take a look at CDC’s and partner resources.

Vaccinations (shots)

Some vaccinations are recommended before you become pregnant, during pregnancy, or right after delivery. Having the right vaccinations at the right time can help keep you healthy and help keep your baby from getting very sick or having lifelong health problems.

3. Take 400 Micrograms of Folic Acid Every Day

Folic acid is a B vitamin. If a woman has enough folic acid in her body at least 1 month before and during pregnancy, it can help prevent major birth defects of the baby’s brain and spine.

Learn more about folic acid »

4. Stop Drinking Alcohol, Smoking, and Using Certain Drugs

Smoking, drinking alcohol, and using certain drugs can cause many problems during pregnancy for a woman and her baby, such as premature birth, birth defects, and infant death.

If you are trying to get pregnant and cannot stop drinking, smoking, or using drugs―get help! Contact your doctor or local treatment center.

Alcohol and Drug Resources

Substance Abuse Treatment Facility Locator
The Substance Abuse and Mental Health Services Administration (SAMHSA) has a treatment facility locator. This locator helps people find drug and alcohol treatment programs in their area.

Alcoholics Anonymous (A.A.)
Alcoholics Anonymous® is a fellowship of men and women who share their experiences, strengths, and hopes with each other so that they can solve their common problem and help others to recover from alcoholism. Locate an A.A. program near you.

Learn more about alcohol and pregnancy »

Smoking Resources

1-800-QUIT-NOW (1-800-784-8669)

Learn more about smoking during pregnancy »

5. Avoid Toxic Substances and Environmental Contaminants

Avoid harmful chemicals, environmental contaminants, and other toxic substances such as synthetic chemicals, metals, fertilizer, bug spray, and cat or rodent feces around the home and in the workplace. These substances can hurt the reproductive systems of men and women. They can make it more difficult to get pregnant. Exposure to even small amounts during pregnancy, infancy, childhood, or puberty can lead to diseases. Learn how to protect yourself and your loved ones from toxic substances at work and at home.

Learn about the effects of toxic substances on reproductive health »

Learn how CDC tracks Children’s Environmental Health »

6. Reach and Maintain a Healthy Weight

People who are overweight or obese have a higher risk for many serious conditions, including complications during pregnancy, heart disease, type 2 diabetes, and certain cancers (endometrial, breast, and colon).1 People who are underweight are also at risk for serious health problems.2

The key to achieving and maintaining a healthy weight isn’t about short-term dietary changes. It’s about a lifestyle that includes healthy eating and regular physical activity.

If you are underweight, overweight, or obese, talk with your doctor about ways to reach and maintain a healthy weight before you get pregnant.

Learn more about healthy weight »

7. Get Help for Violence

Violence can lead to injury and death among women at any stage of life, including during pregnancy. The number of violent deaths experienced by women tells only part of the story. Many more survive violence and are left with lifelong physical and emotional scars.

If someone is violent toward you or you are violent toward your loved ones―get help. Violence destroys relationships and families.

Learn about violence prevention »

8. Learn Your Family History

Collecting your family’s health history can be important for your child’s health. You might not realize that your sister’s heart defect or your cousin’s sickle cell disease could affect your child, but sharing this family history information with your doctor can be important.

Other reasons people go for genetic counseling include having had several miscarriages, infant deaths, trouble getting pregnant (infertility), or a genetic condition or birth defect that occurred during a previous pregnancy.

Learn more about family history »

Learn more about genetic counseling »

9. Get Mentally Healthy

Mental health is how we think, feel, and act as we cope with life. To be at your best, you need to feel good about your life and value yourself. Everyone feels worried, anxious, sad, or stressed sometimes. However, if these feelings do not go away and they interfere with your daily life, get help. Talk with your doctor or another health professional about your feelings and treatment options.

Learn about mental health »

Learn about depression »

10. Have a Healthy Pregnancy!

Once you are pregnant, be sure to keep up all of your new healthy habits and see your doctor regularly throughout pregnancy for prenatal care.

Learn how to have a healthy pregnancy »

References

  1. NIH, NHLBI Obesity Education Initiative. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Available online:
    http://www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.pdf (PDF-1.25Mb)
  2. Moos, Merry-K, et al. Healthier women, healthier reproductive outcomes: recommendations for the routine care of all women of reproductive age. AJOG Volume 199, Issue 6, Supplement B , Pages S280-S289, December 2008.
Pregnant woman sitting in childbearing center

Sexually Transmitted Disease Surveillance, 2020 serves as a reminder that STDs remain a significant public health concern, even in the face of a pandemic. In 2020, COVID-19 significantly affected STD surveillance and prevention efforts. This report reflects the realities of a strained public health infrastructure, while simultaneously providing the most current data on reported cases of STDs in the United States. Trends presented in this report should be interpreted cautiously. 

Chlamydia

In 2020, a total of 1,579,885 cases of Chlamydia trachomatis infection were reported to the CDC, making it the most common notifiable sexually transmitted infection in the United States for that year. This case count corresponds to a rate of 481.3 cases per 100,000 population, a decrease of 13% compared with the rate in 2019. During 2019–2020, rates of reported chlamydia decreased among both males and females, in all regions of the United States, and, except for rates among non-Hispanic persons of multiple races, among all racial/Hispanic ethnicity groups.

Decreases in rates of reported chlamydia in 2020 are unlikely due to a reduction in new infections. As chlamydial infections are usually asymptomatic, case rates are heavily influenced by screening coverage. During the COVID-19 pandemic, many health care clinics limited in-person visits to patients with symptoms or closed entirely, and it is likely that preventive health care visits where STD screening usually happens, such as annual reproductive health visits for young women, decreased. During the initial shelter-in-place orders in March and April of 2020, the number of chlamydia cases decreased substantially when compared to the number of cases reported in 2019 and the deficit persisted throughout the year.

Rates of reported chlamydia are highest among adolescents and young adults. In 2020, almost two-thirds (61%) of all reported chlamydia cases were among persons aged 15–24 years. Decreases in rates of diagnosed and reported chlamydia during 2020 were most noticeable among females aged 15–24 years, one of the populations targeted for chlamydia screening. Although still high, rates of reported chlamydia decreased 15% among 15–19-year-old females and decreased 10% among 20–24-year-old females during 2019–2020.

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