Lung Infections: Types, Symptoms, Causes, Treatment, and Prevention

What Are Lung Infections?

Invasion of harmful microorganisms such as viruses, bacteria, or fungi in the lungs is broadly categorised as a lung infection. It can lead to inflammation of the lung tissues, making it difficult to carry on day-to-day activities. The respiratory tract is a long passage comprising different structures such as bronchi, bronchioles, alveoli, etc., all of which perform varied functions.

Common Types of Lung Infections

Some of the most common types of infections are listed below:

1. Pneumonia

Inflammation and buildup of fluids in the lungs due to bacterial, viral, or fungal infection is referred to as pneumonia. There are different types of pneumonia.

If an individual develops pneumonia via work or a social event, it is termed as community-acquired pneumonia.

• If an individual acquires pneumonia during or after a hospital stay, it is referred to as healthcare-associated pneumonia.
• If an individual develops pneumonia after being on a ventilator, it is referred to as ventilator-associated pneumonia.
• A condition where solid food or liquid goes down into the windpipe deep into the lungs and the individual is not able to cough, it is known as aspiration pneumonia, which affects the lungs.

2. Bronchitis

Inflammation and filling of the lungs with mucus, blocking the airways, is termed bronchitis. The common symptoms associated with bronchitis include difficulty breathing, a constantly runny nose, excessive tiredness, and fever. Infections caused by viruses and bacteria, along with smoking and pollution, are the common causes of bronchitis.

3. Tuberculosis

A serious and chronic condition that affects the lungs is known as tuberculosis. The condition spreads when an ill person coughs or sneezes and transmits tiny droplets, which are taken in or breathed in by a healthy person. The common symptoms associated with tuberculosis include cough with mucus discharge, tiredness, night sweats, pain while breathing, and feelings of ill health.

4. COVID-19

Also known as coronavirus, COVID-19 is caused by a virus known as coronavirus or SARS-CoV-2. It spreads via droplet infection from an ill person to a healthy person. The common symptoms of COVID-19 include an excessive dry cough, shortness of breath, loss of taste, loss of smell, excessive tiredness, throbbing headaches, and digestive issues.

Causes of Lung Infections

Attack by pathogens such as bacteria, viruses, fungi, or parasites remains the most common cause of lung infections. Some of the examples of pathogens responsible for lung infections are:

• Bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, etc.
• Viruses such as Influenza, rhinovirus, SARS-Cov-2, adenovirus, etc.
• Fungi such as Aspergillus, Pneumocystis jirovecii, Histoplasma, etc.
• Parasites such as Paragonimus. 

Symptoms of Lung Infections

There are several different symptoms of lung infections which get highlighted based on the type and severity of the condition and patient’s condition. These include:

• Coughing
• Coughing accompanied with mucus or phlegm
• Production of thick mucus, which may be clear, white, green, or yellowish grey
• Muscle aches or body aches
• Rattling sounds in the lungs
• Difficulty in breathing
• Pain in the chest while breathing
• Wheezing or crackling while breathing
• Excessive chills
• Mild to high-grade fever
• Tiredness due to breathing difficulty
• Unexplained loss of appetite
• Dropping of oxygen levels leading to fingertips and lips turning bluish
• Struggling to keep the heart rate stable
• Confusion in elderly

Diagnosis of Lung Infections

The doctor will use a stethoscope to detect abnormal sounds of the lungs, such as wheezing or crackling, during the first visit. In addition to that, the doctor will also check breathing rate, oxygen levels, and try to obtain a detailed medical history. After that, advanced diagnostic tests are used to diagnose and confirm lung infection. These include:

• Blood tests are used to check for signs of infections. For instance, a high count of white blood cells indicates the presence of a bacterial or viral infection.
• Pulse oximetry is a device that helps in measuring blood oxygen levels to understand if there is any infection that may hamper the functioning of the lungs.
• Chest X-ray is an imaging test which helps in detecting the buildup of fluid or inflammation in the lungs, helping in checking for any infections in the lungs.
• To obtain an even more detailed image, CT or computed tomography scans are used which help in indicating the exact type and extent of lung damage.
• Sputum test, that is, sending the samples of cough or mucus to the laboratory to identify the presence of bacteria, virus, or fungi, is used, which helps in deciding targeted treatment.
• In severe cases, bronchoscopy is used to obtain a look inside the lungs of the patient and collect fluid samples or tissue samples to evaluate further.

Risk Factors for Lung Infections

There are different risk factors which can elevate the risk of lung infections. These include:

• Individuals with weakened immune systems due to health conditions such as cancer, certain medications, or HIV/AIDS are at a greater risk of lung infections.
• Individuals with respiratory conditions such as COPD, cystic fibrosis, or asthma, which are chronic in nature, are at a greater risk of developing lung infections.
• Individuals who smoke and consume alcohol excessively are at a greater risk of developing lung infections, as these agents weaken the immune system of the body.
• Individuals exposed to chemicals, air pollution, or harmful fumes are at a greater risk of developing lung infections.
• Elders are at a greater risk of developing lung infections compared to the younger generation of people.

Treatment for Lung Infections

Different treatment options are available for lung infections. Here’s a list of different treatment options.

• Medications, such as antibacterial or antiviral, are commonly based on the cause of the lung infection. Usually, treatment duration ranges from 5 to 14 days.
• Oxygen therapy delivered via face masks or nasal cannula is also given to patients with abnormally low oxygen levels.
• Symptom management is done via cough suppressants, expectorants, and bronchodilators that help in reducing the phlegm, opening up the airways, and relieving bronchospasms.
• For severe cases, pleural drainage, bronchoscopy, and extracorporeal membrane oxygenation are used. They help in clearing the airways and reducing the risk of respiratory failure.

Complications of Lung Infections

If left untreated or unmanaged, lung infections can lead to different complications based on the type and severity of the infection and the patient’s condition. These include:

• Pleural effusion, characterised by abnormal accumulation of fluids between the layers surrounding the lungs, making it difficult for people to breathe and causing pain in the chest while breathing, is a common complication that arises due to lung infection.
• Another common complication is empyema, characterised by a collection of pus in the pleural space, which can lead to permanent scarring in the lung tissues.
• Localised collection of pus within the tissues of the lungs that were developed due to severe and untreated pneumonia is known as a lung abscess.
• Severe inflammation due to lung infection can lead to buildup of fluid in the alveoli, making it difficult to breathe and reducing the oxygen levels in the patient. The condition is known as acute respiratory distress syndrome.
• In case of lung infections, respiratory failure may also occur when there is inadequate exchange of gas in the respiratory tract, making it a life-threatening complication.
• Chronic and prolonged infections can lead to systemic inflammatory response, causing dysfunction and failure of different organs, characterised by dangerously low blood pressure and mental confusion. The condition is known as sepsis or septic shock.
• Other commonly associated complications due to lung infections include bacteremia or entry of bacteria into the bloodstream, bronchiectasis or permanent widening and damage to the airways, scarring of the lung tissues, and others.

Home Remedies for Lung Infections

There are different home remedies that may help manage lung infections by relieving the symptoms. These include:

• A lot of natural products act as natural expectorants and anti-inflammatories that can help in soothing the irritated airways. Some examples of such natural compounds include honey, turmeric, and warm milk, which act as anti-inflammatories with antioxidant properties.
• Different breathing exercises, such as deep breathing or pursed-lip breathing, can help in clearing the airways and improving the intake of oxygen.
• Gargling with salt water can also help in reducing the inflammation of the throat and clearing the mucus.
• Steam therapy, or inhaling steam from a bowl of hot water, can help loosen the mucus, thereby helping open the airways for optimal breathing.

Prevention of Lung Infections

There are different preventive measures that may help prevent lung infections. These include:

• It is recommended to keep up with the vaccination schedules and obtain vaccines for flu, pneumonia, COVID-19, tuberculosis, and pertussis.
• It is heavily recommended to follow adequate hygienic practices, that is, washing the hands thoroughly with the use of soap or hand sanitizer.
• It is recommended to invest in an air purifier with HEPA filters to reduce the risk of infections.
• It is also recommended to practise social distancing during outbreaks of diseases and avoid close contact with people who are already sick.
• Apart from this, cessation of smoking and limiting alcohol consumption is required to keep the immune system intact.
• Consuming a healthy and nutritious diet with proper hydration helps in improving the immune system.

When Should I See a Doctor for a Lung Infection?

Individuals with symptoms of excessive shortness of breath, pain in the chest, high fever, discolouration of lips or fingernails, difficulty speaking in complete sentences, or coughing blood are recommended to seek medical attention immediately. In addition to this, elder individuals or people with chronic medical conditions or weakened immune systems are required to seek medical care at regular intervals.

Frequently Asked Questions