Respiratory Infections
Infections of the airways and lungs
Quick Facts
- Type: Infectious airway and lung conditions
- Common causes: Viruses and bacteria
- Range: Cold and sinusitis to bronchitis and pneumonia
- Seek urgent care: Trouble breathing, blue lips, high fever
Overview
Respiratory infections are illnesses that affect the parts of the body used for breathing, including the nose, sinuses, throat, voice box, airways, and lungs. They are among the most common infections worldwide and range from mild, self-limiting illnesses to serious conditions that need urgent care.
Doctors often divide them into upper respiratory infections, which affect the nose, sinuses, and throat (such as the common cold, sinusitis, and sore throat), and lower respiratory infections, which affect the airways and lungs (such as bronchitis and pneumonia). Most are caused by viruses, though bacteria are responsible for some. Treatment depends on the type, the cause, and how severe the illness is.
Symptoms
Symptoms vary with the location and severity of the infection but commonly include:
- Runny or blocked nose and sneezing
- Sore throat and cough
- Fever, chills, and body aches
- Fatigue and headache
- Coughing up mucus or phlegm
- Wheezing or chest tightness
- Shortness of breath in more severe or lower-tract infections
Upper infections tend to cause nasal and throat symptoms, while lower infections more often cause cough, chest symptoms, and breathing difficulty. Severe breathing trouble, blue lips, or confusion require emergency care.
Causes
Most respiratory infections are caused by germs spread through respiratory droplets, coughing, sneezing, and contaminated surfaces.
- Viruses: The most common cause, including those responsible for colds, influenza, and many cases of bronchitis and pneumonia.
- Bacteria: Can cause some sinus infections, strep throat, and bacterial pneumonia, sometimes following a viral illness.
- Other germs: Less commonly, fungi and other organisms, especially in people with weakened immune systems.
Risk Factors
- Young children and older adults
- Smoking or exposure to secondhand smoke and air pollution
- Chronic lung conditions such as asthma or COPD
- A weakened immune system
- Close contact with infected people, such as in schools or crowded settings
- Not being up to date on recommended vaccines
Diagnosis
Many respiratory infections are diagnosed from symptoms and a physical exam. Additional tests may be used when needed:
- Listening to the lungs for abnormal breathing sounds.
- Throat or nasal swabs to identify certain viruses or bacteria.
- Chest X-ray when pneumonia is suspected.
- Oxygen level measurement in more severe cases.
- Sputum or blood tests in selected situations.
Treatment
Treatment depends on whether the cause is viral or bacterial and on the severity.
- Rest and fluids: The foundation of care for most viral infections.
- Symptom relief: Pain and fever reducers, saline rinses, and cough care as appropriate.
- Antibiotics: Used only for bacterial infections, since they do not help viral illnesses.
- Antiviral medication: May be prescribed for influenza in certain people.
- Breathing support and hospital care: For severe pneumonia or low oxygen levels.
Most colds and mild infections clear on their own within a week or two, while pneumonia and other serious infections need closer medical management.
Prevention
- Wash hands often and avoid touching the face
- Stay up to date on recommended vaccines, including influenza and pneumonia vaccines where advised
- Cover coughs and sneezes and stay home when sick
- Avoid smoking and secondhand smoke
- Keep chronic lung conditions well managed
When to See a Doctor
See a doctor if you have a high or persistent fever, symptoms that worsen or last beyond about ten days, or coughing up discolored or bloody mucus. Seek emergency care immediately for:
- Difficulty breathing or rapid, labored breathing
- Blue or gray lips, face, or fingertips
- Chest pain or confusion
- A very high fever that will not come down, especially in infants or older adults
Frequently Asked Questions
What is the difference between upper and lower respiratory infections?
Upper respiratory infections affect the nose, sinuses, and throat and include colds, sinusitis, and sore throat. Lower respiratory infections affect the airways and lungs and include bronchitis and pneumonia, which more often cause cough, chest symptoms, and breathing difficulty.
Do respiratory infections need antibiotics?
Most respiratory infections are caused by viruses, and antibiotics do not help viral illness. Antibiotics are used only when a bacterial infection, such as strep throat or bacterial pneumonia, is present. Taking them unnecessarily contributes to antibiotic resistance.
How long do respiratory infections last?
Most colds and mild infections improve within one to two weeks, though a lingering cough can last longer. Pneumonia and other lower-tract infections may take longer and sometimes need closer medical care. Worsening symptoms after improving should be checked.
When is a respiratory infection an emergency?
Seek emergency care right away for difficulty breathing, rapid or labored breathing, blue or gray lips or face, chest pain, confusion, or a very high fever that will not come down, especially in infants and older adults. These can signal a serious infection.
How can I avoid catching respiratory infections?
Wash your hands often, avoid touching your face, cover coughs and sneezes, and stay home when sick. Staying up to date on recommended vaccines and not smoking also lowers your risk and the severity of infection.
References
- Centers for Disease Control and Prevention (CDC).
- World Health Organization (WHO). Respiratory infections.
- Mayo Clinic. Common cold and pneumonia.
- MedlinePlus, U.S. National Library of Medicine. Respiratory tract infections.