Influenza (flu)

Don’t risk the flu — get vaccinated. The flu vaccine protects you, your family and your community, and it helps reduce the risk of severe illness and flu-related complications. In many places the vaccine is free or subsidized for eligible priority groups.

What is influenza (flu)?#

Influenza is a highly contagious viral infection of the respiratory tract that can cause severe illness and life-threatening complications, including pneumonia. It affects people of all ages.

The flu is usually spread by breathing in droplets from coughs and sneezes that contain the virus. It is a seasonal infection that mainly circulates during the local flu season, and flu seasons vary in severity and duration from year to year.

Each year the flu causes many hospitalizations and deaths, and reported figures are widely believed to under-represent the true burden of the disease. Even healthy people can sometimes die from the flu. Some people are at increased risk of serious disease and complications, including young children, older people, pregnant women, and people with a weakened immune system or a chronic medical condition.

Symptoms#

The most common symptoms of the flu are:

• a sudden high fever (38°C/100.4°F or more)
• a dry cough
• body aches, especially in the head, lower back and legs
• chills
• aching behind the eyes
• loss of appetite
• sore throat
• feeling extremely weak and tired, and not wanting to get out of bed

Other symptoms can include a runny or stuffy nose.

The flu is even more likely if you have been in contact with someone who already has it. The flu and other viruses can only be confirmed by a doctor after a nose or throat swab returns a positive result. Because the symptoms of the flu and COVID-19 can be similar, talk to your doctor about whether you need COVID-19 testing.

What to expect with the flu#

Symptoms can come on very quickly and may last several weeks. A bout of the flu often follows this pattern:

• Days 1–3: Sudden fever, headache, muscle pain and weakness, dry cough, sore throat and sometimes a stuffy nose.
• Day 4: Fever and muscle aches decrease. A hoarse, dry or sore throat, cough and possible mild chest discomfort become more noticeable, and you may feel tired or flat.
• Day 8: Symptoms decrease, though cough and tiredness may last one to two weeks or more.

In some cases, complications such as pneumonia and bronchitis develop, which can result in hospitalization and even death. The flu can also make some existing medical conditions worse.

Vaccination#

A yearly flu vaccine is recommended for everyone aged 6 months and over. While not 100% effective, it provides a high level of protection and can reduce symptoms in those who still get sick. Speak to your immunization provider to check whether you are eligible for a free or funded vaccine.

Vaccination may be funded for groups at higher risk of severe complications, which can include:

• children aged 6 months to under 5 years
• pregnant women at any stage of pregnancy
• people aged 65 years or over
• children on long-term aspirin therapy aged 5 to 10 years
• people aged 6 months or over with medical conditions that raise their risk of serious disease, such as cardiac disease, chronic respiratory conditions, immunocompromising conditions, hematological disorders, chronic metabolic disorders, chronic kidney disease and chronic neurological conditions

Other vaccines may be recommended around the same time, such as whooping cough, respiratory syncytial virus (RSV), pneumococcal and COVID-19 vaccines. Speak to your immunization provider for advice about COVID-19 and flu vaccines for children aged 6 months to under 5 years.

Wearing a face mask and practicing good hand hygiene can also help reduce your chances of catching the flu or passing it on.

Should I see a doctor?#

Anyone at higher risk of serious illness who has flu-like symptoms should see their doctor as soon as possible. Most people who are generally healthy won’t need to see a doctor for the flu. As the symptoms are similar to COVID-19, talk to your doctor about testing for COVID-19.

If you have the flu, try to rest, keep up a good fluid intake and manage your symptoms. This will help you recover and prevent dehydration. Your immune system will fight the infection, and symptoms usually clear up on their own.

If you do need to see a doctor, call ahead first so they can make sure no one in an at-risk group is around when you have your appointment. See your doctor if you have any concerns or are in a high-risk group for severe infection.

Seek immediate medical attention if you experience:

• difficulty breathing
• chest pain
• sudden dizziness
• confusion
• severe vomiting
• fever with a rash

How to avoid spreading the flu#

We all have a part to play in stopping the spread of the flu. Aside from getting your flu shot, follow these three simple steps:

1. Cough or sneeze into your elbow. It is a part of your body less likely to touch other surfaces, which helps stop the spread of germs.
2. Wash your hands thoroughly and regularly. Our hands are one of the top spreaders of viruses. The flu virus is carried in almost invisible droplets from saliva, sneezes, coughs and runny noses, and can live on surfaces such as lift buttons or handrails for up to 48 hours. Wash your hands with soap and water for at least 20 seconds, especially after being in a public place or after blowing your nose, coughing, sneezing or using the toilet. If soap and water are not available, use a hand sanitizer containing at least 60% alcohol.
3. Rest and recover at home. If you are sick, stay home and drink plenty of fluids. Avoid going out where you risk spreading the virus to others, and wear a mask if you do need to go out. If you start to experience more serious symptoms, seek medical attention.

Looking after yourself#

The best things you can do when you have the flu are:

• Rest. You will probably feel very weak and tired until your temperature returns to normal (about 3 days). Rest provides comfort and lets your body use its energy to fight the infection.
• Stay at home. Stay away from work, school and any place where you may have contact with others, especially while you are contagious. Adults are usually contagious for around 3–5 days from when the first symptoms appear, and up to 7 days in younger children.
• Drink plenty of fluids. Extra fluids replace those lost through fever and sweating. If your urine is dark, you need to drink more. Try to drink a glass of fluid, such as water, every hour while you are awake.

Medications for the flu#

Antibiotics are not effective against the flu, because it is a virus and antibiotics fight bacteria. However, your doctor may prescribe them if you develop a bacterial infection on top of the flu.

Antiviral medications, if started in the first 2 days after symptoms begin, can shorten the length of your illness. These need to be prescribed by your doctor. Decongestants and simple pain relievers can help you feel better while your immune system fights off the infection.

When buying over-the-counter medication for the flu:

• Buy a remedy that treats only one symptom, so you are not taking substances you don’t need or that may trigger an adverse reaction.
• Read the label and check whether the active ingredient treats your symptoms, the possible side effects, whether it is safe for you given any health conditions, and possible interactions with other medicines (including prescription and over-the-counter medicines, vitamin and mineral supplements, and herbal medicines).
• If you are unsure whether a medication is suitable, talk to your doctor or pharmacist, who can suggest one that is appropriate and safe for you.

Other recovery tips#

• Take simple pain relief, such as paracetamol (acetaminophen) or ibuprofen, as directed on the packet, to ease muscle pain and bring down a fever (unless your doctor says otherwise). Never give any medication that contains aspirin to children under 12 years unless advised by a doctor — the combination of the flu and aspirin in this age group can cause Reye’s syndrome, a very serious condition affecting the nervous system and liver.
• Gargle with a glass of warm water to ease a sore throat. Sucking on sugar-free lollies or lozenges can also help.
• A hot water bottle or heating pad may relieve muscle pain, and a warm bath may be soothing.
• Use saline nose drops or spray to soothe or clear a stuffy nose.
• Do not smoke, as this will irritate your damaged airways.
• Try warm, moist air inhalation. Boil a kettle, wait a minute for the water to cool slightly, then carefully pour the hot water into a bowl on a steady surface such as a table. Put a towel over your head and inhale the warm air for up to 20 minutes. There is no need to add anything to the water. Be careful not to touch the water, and keep it out of reach of children.
• Ask for help if you live alone or care for others — you may need support until you feel better.
• If you buy medicine at the pharmacy to treat your symptoms, check with the pharmacist which one is right for you, and let them know if you have a chronic illness or are taking any other medication.

Key Points#

• The flu vaccine helps reduce the risk of severe illness and flu-related complications.
• The flu causes many hospitalizations and deaths each year, and reported figures likely under-represent the true burden.
• Vaccination is key to protecting yourself and those around you from the flu.
• The most common symptoms include feeling extremely weak and tired, fever, body aches and a dry cough.
• Other symptoms can include a runny or stuffy nose.

Where to get help and trusted information#

For evidence-based global health guidance, see Source: World Health Organization (WHO).