Acute respiratory infection (ARI)

Acute respiratory infections (ARIs) are infections of the parts of the body you use for breathing, such as the sinuses, the throat, the airways and the lungs.

Most ARIs are caused by viruses, and some are caused by bacteria.

Examples of ARIs include:

• common cold
• flu
• RSV
• coronavirus (COVID-19)
• slapped cheek syndrome

Many ARIs get better by themselves, but sometimes a doctor may treat them with antibiotics.

Acute respiratory infection (ARI) can cause several symptoms. The common ones are:

• a new continuous cough
• sneezing
• a blocked or runny nose
• a sore throat
• a headache
• muscle aches
• shortness of breath, tight chest or wheezing
• a high temperature (fever), which is usually about 38°C or higher (100.4°F)
• feeling generally unwell
• feeling tired or having a lack of energy

Less common symptoms of an acute respiratory infection (ARI) include:

• diarrhoea
• loss of appetite
• feeling sick or vomiting

There's a separate page if your child has cold or flu symptoms. You can also get advice about fever in children.

Some acute respiratory infections (ARI), like the common cold and RSV, may also lead to middle ear infection, sinusitis and, in younger children, croup.

If you have symptoms of an acute respiratory infection (ARI), you must:

• stay away from people at increased risk of becoming more unwell from respiratory infections, if possible
• not visit hospitals or care homes

You may still have a cough or feel tired after your other symptoms have gone. That doesn't mean you're still infectious to others.

You or your child:

• have severe or sudden chest pain that isn't going away (it may feel like pressure, tightness or squeezing)
• have severe difficulty breathing (for example, you struggle to speak without pausing, or you are gasping or choking)
• are coughing up blood (haemoptysis)
• collapse, faint, or have a seizure or fit for the first time
• feel more drowsy than usual or find it more difficult to wake up
• have lips or skin that are turning pale, blue or grey (on brown or black skin this is easier to see on the palms of the hands)
• have blotchy or mottled skin
• have a rash that does not fade when you roll a glass over it (use the glass test)

Speak to a doctor if you:

• have symptoms that are not getting better, or you're concerned about them
• are worried about your child
• have had a high temperature for more than 3 days
• have a temperature below 36°C
• have breathlessness that is not getting better
• have had a cough for more than 3 weeks
• have symptoms that are not improving or are affecting your daily life
• have a long-term medical condition (for example, diabetes, or a heart, lung or kidney condition)
• have a weakened immune system (for example, because you're having chemotherapy)

Most acute respiratory infections (ARIs) clear up within 3 weeks. While you wait for the infection to pass, there are a few things you can do to ease your symptoms.

• rest
• drink plenty of fluids
• eat healthily
• take over-the-counter pain relief, like paracetamol or ibuprofen, to ease a high temperature and aches
• use decongestant sprays or tablets to ease a blocked nose
• use extra pillows to raise your head while you sleep, which makes breathing easier and helps clear mucus from your chest
• try remedies like gargling with salt water and sucking on menthol sweets

• don't smoke, as it can make your symptoms of an acute respiratory infection worse
• don't take paracetamol and flu remedies that contain paracetamol at the same time
• don't give aspirin to children under 16

You can talk to a pharmacist about acute respiratory infection (ARI) and the treatments you can get for it. The pharmacist can also tell you whether your symptoms mean you should see a doctor.

How an acute respiratory infection is treated depends on what's causing it.

If a virus is behind the infection, as with the common cold, your doctor won't prescribe antibiotics. If bacteria are the cause, for example in a chest infection, your doctor may prescribe antibiotics.

Some conditions can raise your chance of becoming seriously ill. You may be at higher risk of acute respiratory infection (ARI) if you have:

• Down's syndrome, or another chromosomal disorder that affects your immune system
• certain types of cancer, or have received treatment for certain types of cancer
• sickle cell disease
• certain conditions affecting your blood
• chronic kidney disease (CKD), stage 4 or 5
• severe liver disease
• had an organ transplant
• certain autoimmune or inflammatory conditions (like rheumatoid arthritis or inflammatory bowel disease)
• HIV or AIDS and have a weakened immune system
• a condition affecting your immune system
• a condition affecting the brain or nerves, like multiple sclerosis, muscular dystrophy, motor neurone disease, myasthenia gravis, Huntington's disease, Parkinson's disease or certain types of dementia
• certain lung conditions or treatments for lung conditions

If you think you're at higher risk, speak to your doctor or specialist, who can confirm it.

There are some simple things you can do to help stop an acute respiratory infection (ARI) from spreading to other people.

• cover your mouth and nose when you cough or sneeze
• wash your hands often with soap and water for 20 seconds, or use hand sanitiser, after you cough, sneeze or blow your nose, and before you eat or handle food
• clean the things people touch a lot, like door handles and remote controls, and shared areas such as kitchens and bathrooms, on a regular basis
• open the windows to let fresh air into rooms you have been in
• stay at home until your fever has gone (if you had one) and you no longer need medicine to bring it down
• if you have been asked to attend a medical or dental appointment in person, tell them about your symptoms before you go
• let people you've recently been in contact with know that you're unwell, so they can watch for symptoms, especially if they're at higher risk of getting ill from a respiratory infection
• tell anyone who needs to come into your home that you have respiratory symptoms
• wear a face mask or face covering if you have to leave your home while you're unwell
• try to avoid busy or crowded spaces with poor ventilation

• if you can avoid it, don't have close contact with anyone who is at increased risk of becoming more unwell from an acute respiratory infection (ARI), especially people with a weakened immune system

Vaccination is one of the best ways to protect yourself from becoming seriously ill with an acute respiratory infection.

• flu vaccine
• coronavirus (COVID-19) vaccine
• RSV vaccine for adults aged 75 to 79
• RSV vaccine during pregnancy
• child flu vaccines