Published: 18 Jun 2025

ICD9: 465.9      ICD10: J06.9      ICD11: CA45

A respiratory infection is an infection that affects the parts of the body involved in breathing, such as the sinuses, throat, airways, or lungs.
These infections are usually caused by viruses or bacteria.

Here's a breakdown of key aspects of respiratory infections:

Types of Respiratory Infections:

Upper Respiratory Infections (URIs): These affect the nose, sinuses, pharynx (throat), larynx (voice box), and trachea (windpipe). Common examples include:
The Common Cold: Usually caused by rhinoviruses.
Sinusitis: Inflammation of the sinuses, often caused by viruses or bacteria.
Pharyngitis (Sore Throat): Can be caused by viruses (like the common cold or flu) or bacteria (like strep throat).
Laryngitis: Inflammation of the larynx, causing hoarseness.
Tonsillitis: Inflammation of the tonsils.
Epiglottitis: Inflammation of the epiglottis, which can be life-threatening (more common in children, but rarer due to vaccination).
Croup: A viral infection of the upper airway, common in young children, causing a characteristic barking cough.

Lower Respiratory Infections (LRIs): These affect the bronchi (airways that branch from the trachea) and lungs. Examples include:
Bronchitis: Inflammation of the bronchial tubes. Can be acute (usually viral) or chronic (often related to smoking or other irritants).
Pneumonia: Infection of the lungs, which can be caused by bacteria, viruses, or fungi.
Bronchiolitis: Inflammation of the small airways (bronchioles) in the lungs, common in infants and young children, often caused by RSV (respiratory syncytial virus).
Influenza (Flu): Caused by influenza viruses.

Causes:

Viruses: The most common cause of respiratory infections, especially URIs. Examples include rhinoviruses (common cold), influenza viruses (flu), respiratory syncytial virus (RSV), adenoviruses, and coronaviruses (including those that cause COVID-19).
Bacteria: Can cause infections like strep throat, bacterial pneumonia, and some cases of sinusitis. Examples include *Streptococcus pneumoniae*, *Haemophilus influenzae*, and *Mycoplasma pneumoniae*.
Fungi: Less common, but can cause pneumonia, especially in people with weakened immune systems.

Symptoms:

Symptoms vary depending on the specific infection and the part of the respiratory system affected, but common symptoms include:

Cough: Dry or productive (producing mucus).
Sore Throat: Pain or scratchiness in the throat.
Runny or Stuffy Nose: Nasal congestion and discharge.
Sneezing: Forceful expulsion of air through the nose and mouth.
Fever: Elevated body temperature.
Headache: Pain in the head.
Body Aches: Pain and stiffness in the muscles.
Fatigue: Feeling tired and weak.
Shortness of Breath: Difficulty breathing.
Wheezing: A whistling sound during breathing.
Chest Pain: Discomfort or pain in the chest.
Loss of Smell or Taste: Common with COVID-19 and sometimes other viral infections.

Transmission:

Respiratory infections are typically spread through:

Airborne droplets: Released when an infected person coughs, sneezes, talks, or sings. These droplets can be inhaled by others nearby.
Direct contact: Touching surfaces contaminated with the virus or bacteria and then touching your face (eyes, nose, or mouth).

Diagnosis:

Diagnosis often involves:

Physical Examination: A doctor will listen to your lungs, check your throat, and assess your symptoms.
Medical History: Discussing your symptoms and any relevant medical conditions.
Testing (Sometimes):
Rapid Antigen Tests: For influenza, strep throat, and COVID-19.
PCR Tests: More sensitive tests for viruses like influenza, RSV, and COVID-19. These detect the genetic material of the virus.
Throat Swab: To test for strep throat.
Chest X-ray: To diagnose pneumonia or other lung conditions.
Sputum Culture: To identify bacteria in the sputum (phlegm) in cases of pneumonia.

Treatment:

Treatment depends on the cause and severity of the infection:

Viral Infections: Often treated with supportive care:
Rest: Getting plenty of sleep.
Fluids: Drinking plenty of water, juice, or broth.
Pain Relievers: Over-the-counter medications like acetaminophen (Tylenol) or ibuprofen (Advil) to relieve fever, headache, and body aches.
Decongestants: To relieve nasal congestion.
Cough Suppressants: To relieve coughing (use with caution, especially in children).
Antiviral Medications: May be prescribed for influenza or COVID-19, especially for people at high risk of complications.
Bacterial Infections: Treated with antibiotics prescribed by a doctor. It's important to take the entire course of antibiotics as prescribed, even if you start feeling better.
Severe Cases: May require hospitalization, oxygen therapy, or other medical interventions.

Prevention:

Vaccination: Annual flu vaccine, COVID-19 vaccines, and vaccines against pneumonia can help prevent these infections.
Handwashing: Wash your hands frequently with soap and water for at least 20 seconds.
Avoid Touching Your Face: Especially your eyes, nose, and mouth.
Cover Your Mouth and Nose: When you cough or sneeze, use a tissue or your elbow.
Social Distancing: Avoid close contact with people who are sick.
Mask Wearing: Wearing a mask in public places can help prevent the spread of respiratory droplets.
Stay Home When Sick: To avoid spreading the infection to others.
Maintain a Healthy Lifestyle: Get enough sleep, eat a healthy diet, and exercise regularly to boost your immune system.

When to See a Doctor:

It's important to see a doctor if you experience any of the following:

Difficulty breathing or shortness of breath
Chest pain
High fever (over 103°F or 39.4°C)
Persistent cough that doesn't improve after a few weeks
Coughing up blood
Bluish lips or face
Severe headache or stiff neck
Dehydration (signs include decreased urination, dizziness, and dry mouth)
Worsening of symptoms despite home treatment

This information is for general knowledge and informational purposes only, and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.