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Respiratory tract infection

Page last reviewed: 13/07/2011

Respiratory tract infections are a common cause of illness. The most widespread respiratory tract infection is the common cold.

The respiratory tract

The respiratory tract is a general term that is used to describe all the parts of the body that are involved in helping a person to breathe. Health professionals generally make a distinction between:

  • the upper respiratory tract
  • the lower respiratory tract

Upper respiratory tract

The upper respiratory tract consists of:

  • the nose
  • the sinuses - air-filled cavities that are found inside the cheekbones and forehead
  • the mouth (including the tonsils)
  • the throat
  • the pharynx - which is at the back of the throat and prevents foreign objects, such as food, falling down into the lungs
  • the larynx or "voice box" - which is the part of the throat that contains the vocal cords

Common upper respiratory tract infections include:

  • the common cold
  • sore throat  - usually due to an infection of the pharynx (pharyngitis)
  • tonsillitis - infection of the tonsils
  • sinusitis - infection of the sinuses
  • laryngitis - infection of the larynx

Lower respiratory tract

The lower respiratory tract consists of:

  • the trachea (windpipe) - the tube that connects the throat to the lungs
  • the bronchi - the two branches that the trachea divides into as it enters the lungs
  • bronchioles - the tiny airways that are found throughout the lungs
  • the alveoli - tiny air sacs at the end of the bronchioles

Common lower respiratory tract infections (LTRIs) include:

  • bronchitis - infection of the bronchi, and
  • pneumonia - infection of the bronchioles and alveoli

There are also certain types of infection, such as flu, that can affect both the upper and lower respiratory tract.

How common are respiratory tract infections?

Respiratory tract infections are very common. They are believed to be one of the main reasons why people visit their GP or pharmacist.

The respiratory tract is much more vulnerable to infection than other parts of the body. This is because it is easy for bacteria or viruses to enter the tract when someone breathes in.

Respiratory tract infections are more common during the winter. This is possibly due to the fact that during the winter months people are more likely to stay inside and in close contact with each other.

Children tend to get more upper respiratory tract infections than adults. This is because they have not yet built up immunity to the many viruses that can cause colds.


The outlook for respiratory tract infections is generally good. Most infections are self-limiting, which means that they will pass without the need for treatment.

However, extra care and additional treatment may be required for people who are more vulnerable to the effects of infection. Those who may require this include:

  • the very young
  • the elderly
  • people with a pre-existing lung condition
  • people with a weakened immune system

A number of vaccines are available for some of the viruses and bacteria that cause infection, such as the flu vaccine and the pneumococcal vaccine (pneumococcal bacteria is a family of bacteria that can cause pneumonia). See Respiratory tract infection - Prevention for more information on preventing respiratory tract infections.

Acute means occurring suddenly or over a short time.
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.

Page last reviewed: 13/07/2011

Upper respiratory tract infection

A cough is the most common symptom of an upper respiratory tract infection. Other symptoms include:

  • headaches
  • stuffed or runny nose
  • sore throat
  • sneezing
  • muscle aches and pain

The symptoms of an upper respiratory tract infection usually pass within one to two weeks.

Lower respiratory tract infections

As with an upper respiratory tract infection, the main symptom of a lower respiratory tract infection is a cough, although it is usually more severe and more productive (bringing up phlegm and mucus). Sometimes the mucus is blood-stained.

Other symptoms of a lower respiratory tract infection include:

  • a tight feeling in your chest
  • breathlessness
  • wheezing
  • sore throat
  • fever and chills
  • headaches
  • blocked nose and sinuses
  • aches and pains

When to seek medical advice

Most respiratory tract infections do not require medical attention and can be treated at home.

However, it is recommended that you visit your GP if:

  • Your symptoms suggest that you may have pneumonia, such as coughing up bloody mucus and phlegm.
  • You are feeling very unwell.
  • You have a pre-existing heart, lung, liver, or kidney condition.
  • You have a condition that affects your nervous system, such as multiple sclerosis.
  • You have cystic fibrosis.
  • You have a weakened immune system.

It is also recommend that you visit your GP if you are 65 or over and have at least two of the factors listed below, or you are 80 or over and have one of the factors listed below:

  • You have been admitted to hospital at some time during the past year.
  • You have type 1 or type 2 diabetes.
  • You have a history of heart failure.
  • You are taking a type of steroid medication called glucocorticoid.
An ache is a constant dull pain in a part of the body.
A high temperature, also known as a fever, is when someone's body temperature goes above the normal 37C (98.6F).
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Page last reviewed: 13/07/2011

Most upper respiratory tract infections are caused by viruses. There are more than two hundred different viruses that can cause a respiratory tract infection. However, the most common viruses belong to one of two groups: 

  • rhinoviruses
  • coronaviruses

The most common respiratory tract infection is a cold. The number of different viruses that can cause a cold is the reason why it is possible to have several colds, one after the other, with each one being caused by a different virus.

Most lower respiratory tract infections are also caused by viruses. The exception is pneumonia, which is usually caused by streptococcus pneumoniae bacteria.

How infections spread

Respiratory tract infections can be spread in several ways. If you have an infection such as a cold, tiny droplets of fluid containing the cold virus are launched into the air whenever you sneeze, cough or speak. If these are breathed in by someone else, they may also become infected.

Infections can also be spread through direct and indirect contact. If you have an infection such as a cold or the flu, and you touch your nose or eyes before touching someone else, you may pass the virus on to them. Alternatively, if you touch an object, such as a door handle, or telephone, the virus may be transferred to the object. If someone touches the object a short time later, and then touches their mouth, nose or eyes, they may become infected.

Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some others are good for you.
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.

Page last reviewed: 13/07/2011

Upper respiratory tract infections are usually obvious from the common cough and cold symptoms, and do not usually require a medical diagnosis.

Lower respiratory tract infections may be diagnosed by your GP after asking you about your symptoms and listening to your chest with a stethoscope. If you have a lower respiratory tract infection, your breathing will sound crackly.

Your GP may also listen to your chest by tapping it. If your lungs are filled with fluid, they will produce a different sound compared to if they contain air.

Further testing for a lower respiratory tract infection is usually only required if your symptoms are particularly severe, or if you fail to respond to treatment.

In these circumstances, you may be given a blood test and X-rays will be taken of your chest.


Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Page last reviewed: 13/07/2011

Self care

Most respiratory tract infections can be treated using some self-care techniques, such as those outlined below.

  • Paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can help to relieve the symptoms of pain and fever.
  • Drink plenty of non-alcoholic fluids to keep yourself hydrated - this is particularly important for children. Water is best, although warm drinks can be soothing.
  • Try to rest and avoid strenuous activity.
  • Keep the room at a comfortable temperature, but make sure that fresh air is circulating.
  • A cough medicine may help to soothe a ticklish or dry cough. Over-the-counter (OTC) products that are available from your local pharmacist are often sold as combined remedies for treating a cough and cold. Preparations may contain several ingredients, so you should always follow the manufacturer's instructions to ensure that you take the correct dose for your symptoms, and beware that using paracetamol containing preparations simultaneously could result in accidental overdose.
  • Smoke irritates the nose and throat. Therefore, try to avoid being around people who smoke, and stay away from smoke-filled environments. If you are a smoker, try not to smoke while you are feeling unwell, and consider quitting.
  • Raising the head of your bed slightly, by placing a pillow under the mattress, may help reduce coughing at night.

Contact your GP if your symptoms are severe or do not improve within two weeks.

Antibiotics are not usually recommended

Antibiotics are not usually recommended for treating respiratory tract infections. This is because:

  • Most respiratory tract infections are not caused by bacteria.
  • Even if your respiratory tract infection is caused by bacteria, antibiotics have proven to be no more effective in treating these cases than paracetamol, and they may cause unpleasant side effects.
  • Over-using antibiotics to treat minor ailments can make them less effective in the treatment of more serious, or life-threatening, conditions.

Who should take antibiotics?

Antibiotics are only recommended if:

  • You have pneumonia because this is usually caused by a bacterial infection.
  • You have a pre-existing health condition.
  • There are personal circumstances that could lead to serious complications arising from a respiratory tract infection.

For example, antibiotics may be recommended if:

  • You have a condition such as HIV, which weakens your immune system.
  • You are taking a medicine such as an immunosuppressant, which weakens your immune system.
  • You are currently undergoing chemotherapy treatment for cancer.
  • You have a history of heart, lung, liver, neurological or kidney disease or other conditions which weaken your ability to fight infections.
An ache is a constant dull pain in a part of the body.
Angina is chest pain caused by a reduced flow of blood to the heart, typically resulting from heart disease.
Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. For example amoxicillin, streptomycin and erythromycin.
Decongestant medicine relieves congestion by reducing the swelling of the lining the nose and sinuses and drying up the mucous.
Dehydration is an excessive loss of fluids and minerals from the body.
Dose is a measured quantity of a medicine to be taken at any one time, such as a specified amount of medication.
A high temperature, also known as a fever, is when someone's body temperature goes above the normal 37°C (98.6°F).
High blood pressure
Hypertension is when the pressure of the blood in your bloodstream is regularly above 140/90 mmHG.
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
Palpitations refer to an irregular heartbeat, or the sensation of skipped or extra heartbeats.
The thyroid is a jointed piece or cartilage that enclosed the vocal cords and forms the Adam's apple in men.

Page last reviewed: 13/07/2011

Most respiratory tract infections, with the exception of pneumonia and the flu, do not cause complications. Some of the complications that are associated with pneumonia and flu are outlined below.


Pleurisy, pleuritic pain and pleural effusion

Pleurisy is when the two thin linings between your lungs and your ribcage (the bones in your chest) become inflamed. Pleurisy can be caused by lung conditions such as pneumonia.

Sometimes, the symptoms of severe pneumonia can include pleuritic pain, which is a sharp, stabbing pain in your chest that occurs in one place when you breathe in. This can also be a symptom of pleurisy.

Less commonly, fluid can build up in the space between your lungs and the wall of your chest. This is known as a pleural effusion. If this fluid becomes infected (empyema), it will usually be drained using a needle or a thin tube.

Other complications

Other complications of pneumonia can include:

  • deep vein thrombosis (DVT)
  • lung abscess
  • blood infection, such as septicaemia or bacteraemia

Blood infections can make you very ill and normally need to be treated in hospital.

Rarely, pneumococcal pneumonia can cause an infection of the membranes that cover the brain (pneumococcal meningitis).

The flu

The most common complication of flu is a secondary bacterial chest infection which develops in addition to the viral infection. Occasionally, this can become serious and develop into pneumonia. A course of antibiotics will usually be successful in curing the infection but sometimes it can become life-threatening, particularly in those who are frail and elderly. Other serious complications of flu are uncommon.

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Drowsiness is when someone feels extremely tired and uncontrollably near to sleep.
A high temperature, also known as a fever, is when someone's body temperature goes above the normal 37C (98.6F).
Wheezing is the whistling sound made during breathing when the airways are blocked or compressed.

Page last reviewed: 13/07/2011

Stopping the spread of infection

If you develop a respiratory tract infection, it is important to take steps to prevent spreading the infection to other people. These steps are outlined below.

  • Washing your hands regularly and thoroughly, particularly after touching your nose or mouth, and before handling food.
  • Sneezing and coughing into tissues. This will help prevent the virus-containing droplets from your nose and mouth entering the air where they can infect others. Throw away used tissues immediately, then wash your hands.
  • Do not share cups or kitchen utensils with others. Use your own cup, plates and cutlery at mealtimes. These are safe for others to use again after washing them in the usual way.


There are currently three vaccines available  - two for pneumonia and one for the flu - that can provide protection against these two respiratory tract infections. See www.immunisation.ie

Pneumococcal conjugate vaccine (PCV)

The PCV is safe, although about one in 10 children will experience some redness and swelling at the site of the injection and a mild fever. However, these symptoms will pass quickly.

Speak to your GP or health nurse if you are not sure whether your child has received their PCV.

Pneumococcal polysaccharide vaccine (PPV)

Who should be vaccinated with PPV23 Pneumococcal vaccine?

Those with the following conditions should be vaccinated with PPV23.

Everybody aged 65 years and over

Also those aged over 2 years with ;

  • Diabetes mellitus
  • Chronic heart, respiratory or liver disease
  • Chronic renal disease, nephrotic syndrome, renal transplant
  • Sickle cell disease
  • Those with missing or non functioning spleens
  • Disorders of the immune system including cancer
  • People receiving chemotherapy or other treatments that suppress the immune system
  • Persons with HIV infection or AIDS
  • Those who have received or are about to receive cochlear transplants

PPV23 vaccination is not recommended for healthy children and adults as they are at low risk of pneumococcal disease 

 Healthy adults usually require only one dose of PPV. However, those with weakened immune systems, or spleen disorders, may require additional booster doses. Your GP will be able to advise you about this.

After you have had your PPV, you may experience some pain and inflammation at the site of the injection. This should only last for between one to three days. Less commonly, some people report the symptoms of a mild fever. Again, this should pass quickly.

The flu

Who should be vaccinated?

Vaccination against flu is strongly recommended for:

  • persons 65 and over,
  • those with a long-term medical condition such as diabetes, heart or lung disease,
  • people whose immune system is impaired due to disease or treatment
  • residents of nursing homes and other long stay institutions
  • persons with a body mass index (BMI) over 40
  • pregnant women.(can be given at any stage of pregnancy),
  • healthcare workers
  • carers
  • people with regular close contact with poultry, water fowl or pigs.

Contact your local GP surgery if you think that you should have a flu vaccination.

Quit smoking

Smoking damages your lungs. This means that they can become infected more easily.

If you smoke, stopping is the best thing that you can do to prevent developing respiratory tract infections.

For information and support in quitting smoking you can·Visit www.quit.ie the HSE Quit website which aims to encourage smokers to quit. The website includes a Quitplan which you can sign up to that will support you during the quitting process. Join www.facebook.com/HSEquit· Call the National Smokers Quitline 1850 201 203·Contact your local HSE smoking cessation counsellor (see www.quit.ie)·Talk to your GP or Pharmacist who may advise on using nicotine replacement therapy or other medications to help you make that quit attempt successful.  

Immune System

The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.

Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
Sneezing is an involuntary expulsion of air and bacteria from the nose and mouth.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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