Lung Infections: Common Types and How to Treat Them

A lung infection happens when a virus, bacteria, or fungus gets into the lungs. Immune cells race to the airways to fight the infection, causing inflammation. Chest congestion, difficulty breathing, coughing, wheezing, and fever are the result.

Lung infections can be caused by pneumonia, influenza, COVID-19, the common cold, and other upper respiratory illnesses.

Most lung infections are treatable with antibiotics or antivirals, and mild infections often resolve on their own. In some cases, though, lung infections can be severe and lead to hospitalization and even death.

This article explains the types of lung infections. It discusses the different symptoms, causes, and treatments for lung infections and when to see a doctor.

Verywell / Shideh Ghandeharizadeh

Pneumonia

Pneumonia is a lung infection that affects the smallest of airways (alveoli) where the exchange of oxygen and carbon dioxide takes place.

Pneumonia can be a mild illness that's easily treated at home, but can also be a life-threatening infection that requires intensive care.

Pneumonia symptoms can include a cough with rust-colored or bloody phlegm, high fever, chest pain, and fast heart and respiratory rates.

The Flu

Seasonal influenza—or "the flu"—is one of the most common lung infections. Both influenza A and influenza B viruses are spread through droplets that come out of the body when a person coughs, sneezes, or even talks. That's why the flu is very contagious.

The flu can cause a sore throat, runny nose, fever, chills, body aches, cough, and fatigue.

COVID and Other Coronaviruses

The COVID-19 pandemic made people more aware of coronaviruses, but the one that causes COVID (SARS-CoV-2) is just one of several coronaviruses that infect humans.

Other respiratory illnesses in humans that are caused by coronaviruses are severe acute respiratory syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS).

Common Cold

The common cold is responsible for 60% to 80% of school absences in children and 30% to 50% of time lost from work for adults.

During the first six years of life, children have, on average, six to eight colds per year. For most healthy adults, it drops down to three to four colds per year.

Other Types of Lung Infections

Lung infections are grouped into different types depending on how they affect the lungs and airways.

Some organisms are more likely to cause a certain type of lung infection, but there can also be some overlap between them. For example, some viruses can cause bronchitis and pneumonia.

Bronchitis

Bronchitis is an infection of the large airways (bronchi) that travel between the windpipe (trachea) and the smaller airways.

Bronchitis is most commonly caused by a viral infection. In 1% to 10% of cases, a bacterial infection is the cause.

Bronchiolitis

Bronchiolitis is an infection of the smaller airways (bronchioles) between the larger bronchi and the tiny alveoli where the exchange of oxygen and carbon dioxide takes place.

Bronchiolitis is common in children under two years old and is the leading cause of hospitalizations of infants during the first year of life. That said, most children do not need to be hospitalized if they get sick with it.

After recovery, children who have had bronchiolitis may have an increased risk of developing recurrent wheezing or asthma during childhood and even into adulthood.

Enterovirus

Non-polio enteroviruses are a group of common viruses that can cause lung infections. They also cause hand, foot, and mouth disease (enterovirus A71), and severe infections in other parts of the body like myocarditis (inflammation of the heart), meningitis (inflammation of the protective layer around the brain), and encephalitis (brain infection or inflammation).

Lung infections caused by enterovirus often start with cold-like symptoms such as a fever, runny nose, body aches, and sometimes a rash.

Croup

Croup affects the structures above the lungs (larynx and trachea) but can also involve the bronchi. It is more common in children.

Croup is usually caused by viruses, including common cold viruses and respiratory syncytial virus (RSV) but can also be caused by a bacterial infection.

The symptoms of croup often begin with a low-grade fever and runny nose, followed by the characteristic barking cough that gets worse at night.

Whooping Cough (Pertussis)

Whooping cough (pertussis) is often thought of as a vaccine-preventable lung infection of the past, but people still get it today.

Whooping cough can cause mild to severe illness, but it's mostly of concern for infants and young children—around 50% of babies under 12 months of age who get whooping cough need to be in the hospital.

About a fourth of babies and young children who get whooping cough will develop pneumonia. Less commonly (0.3%), complications of whooping cough such as encephalitis may occur.

Could a Lung Infection Be Whooping Cough?

You should know the signs and symptoms of whooping cough, even if you and your family have been vaccinated against it. While it can be a serious lung infection, early diagnosis and treatment can help make the cough less severe.

Tuberculosis

Tuberculosis (TB) is a lung infection that is more common in developing regions of the world. It is caused by a bacteria called Mycobacterium tuberculosis.

There are around 8,900 active TB infections in the United States each year, but the number of cases is the lowest it's been since we started keeping track in 1953.

Lung Infection Symptoms

A lung infection, regardless of type or cause, tends to cause certain symptoms. Here are some of the most common symptoms of a lung infection:

Cough: A cough that is dry (nonproductive—does not bring up mucus) or "wet" (productive); can be mild or severe.
Mucus production: Mucus can be clear, yellow, green, brown, or rust-colored and may have no odor or a foul odor.
Wheezing: Wheezing when breathing out but sometimes when breathing in, too. A different sound—a higher pitched than wheezing called stridor—may happen when breathing in. Stridor is common with infections in the airways above the lungs, like the windpipe (trachea).
Fever: Temperature can be low-grade (less than 100 degrees F), high, or very high.
Chills or rigors (shaking chills): Chills can occur as a fever goes up, and sometimes sweats (which can be drenching) may come on as the fever goes down.
Upper respiratory symptoms: Nasal congestion, sore throat, hoarseness, laryngitis, and headaches commonly occur, especially with viral infections.

Other possible symptoms of a lung infection include:

Less Common Symptoms

There are also some less common, but still important to know, symptoms of a lung infection:

When to See a Healthcare Provider

Viral lung infections, like influenza and the common cold, often clear on their own. The following symptoms should be evaluated by your healthcare provider:

Chest pain (other than a mild ache from coughing)
Confusion or falls (in older adults)
Coughing up blood or rust-colored sputum
Fast pulse (a heart rate greater than 100 beats per minute) or palpitations
Fever over 102 degrees F that persists longer than three days
Lightheadedness
Nausea and vomiting
Poor feeding or lethargy (infants)
Rapid respiratory rate
Shortness of breath (especially at rest)
Signs of dehydration such as thirst, dry lips, or lack of urination
Symptoms that do not start getting better after two weeks

How Lung Infections are Diagnosed

Lung infections are often diagnosed by a primary care provider. After listening to your lungs, your healthcare provider may take:

A nasal or throat swab
A sample of the stuff you cough up (sputum)
Blood

These fluids can help identify the cause of the infection—for example, bacteria and viruses.

Other tests will depend on the cause of the infection, how severe your symptoms are, and whether you have any other health conditions or concerns.

They may want to test your lung function by having you breathe into a special device (spirometry) or take images of your chest (X-ray or CT scan).

Risk Factors for Lung Infections

Risk factors for lung infections vary based on the type, but there are certain things that can increase your risk of lung problems in general.

Common Risk Factors

Some of the most common risk factors for lung infections include:

Smoking or exposure to secondhand smoke
Exposure to air pollution or dust at work
A history of asthma or allergies
Crowded living conditions
Winter months in the northern hemisphere
Dry mucous membranes
Gastroesophageal reflux disease (GERD)
Anatomical differences in the face, head, neck, or airways (e.g., nasal polyps or a deviated septum)
Lower socioeconomic status
Malnutrition
Not being vaccinated (e.g., pneumococcal vaccines in children or the pneumonia shot in eligible adults)

Risk Factors in Children

Risk factors for lung infections in kids include:

Greater exposure to infections at daycare or school, or having multiple siblings
Being male
Prematurity
Bottle feeding instead of breastfeeding
Pacifier use
Age (children under the age of 6 are more susceptible in general, and bronchiolitis occurs most often in children under the age of 2)
Children born to people who smoked during pregnancy
Congenital heart and/or lung diseases

Less Common Risk Factors

While these risk factors for lung infections are less common, they're still important to keep in mind:

Swallowing disorders that lead to breathing in the contents of the mouth or stomach (aspiration)
Lung diseases (e.g., bronchiectasis, emphysema, alpha-1-antitrypsin deficiency, and cystic fibrosis)
Cancer, especially blood-related cancers (e.g., leukemias and lymphomas)
Primary immunodeficiency syndromes (e.g., selective IgA deficiency)
Secondary immunosuppression (e.g., from medications, cancer treatment, HIV, etc.)
Absence of a spleen (e.g., surgical removal or conditions such as hereditary spherocytosis)
Anatomical problems involving the face, head, neck, or airways

Lung Infection Treatment

The treatment for a lung infection depends on what is causing it and how sick a person is, as well as whether they have any other health conditions.

Home Remedies

Home remedies for lung infections include:

Prescription Medications and Hospital Treatment

Bacterial lung infections can be treated with antibiotics, but viral lung infections need to "run their course." However, people with lung infections from any cause may need medical treatment if they have severe symptoms.

For example, people who develop narrowing of the airways with a lung infection (reactive airway disease) may need inhalers that open the airways and corticosteroids to help with inflammation.

People who develop low oxygen levels (hypoxia) from a lung infection might need oxygen therapy, and severe cases may need assisted breathing or mechanical ventilation to help with breathing.

Viral Lung Infections

With viral lung infections, treatment is about helping a person feel as comfortable as possible while they are healing. Lung infections caused by a virus cannot be treated with antibiotics.

Here are a few examples of how different viral lung infections might be treated:

For someone with influenza A, treatment with Tamiflu (oseltamivir) may reduce the severity and duration of the infection if it's started early.
For very high-risk children with bronchiolitis from RSV, a monoclonal antibody treatment might be given.
There are different COVID-19 treatments being tried but we're still learning about which ones help and which ones do not. If your provider thinks you are at risk for complications, they might want you to take antiviral medications.

Bacterial Lung Infections

Antibiotics are the mainstay of treatment for bacterial lung infections. The antibiotic that will be used will depend on which bacteria is causing the infection.

In some cases, a provider may choose to start antibiotics while they are waiting for tests to come back. Once they know which bacteria is the cause of the infection, they might change the antibiotic.

Depending on how sick a person is, they might be able to take the medication by mouth (oral antibiotics) or they might need to have it through an IV.

The timing is also important. For example, with pneumonia, antibiotics need to be started as soon as possible.

Fungal and Parasitic Lung Infections

Anti-fungal medications such as Diflucan (fluconazole), Nizoral (ketoconazole), or Noxafil (posaconazole) are used to treat fungal lung infections.

Parasitic lung infections are treated with anti-parasitic medications. The medication chosen will depend on the parasite that's causing the infection.

Prevention

Lung infections cannot always be prevented, but there are things you can do to lower your risk.

Vaccines

People who are at high risk for complications from lung infections should stay up-to-date on their immunizations. Vaccines that help to prevent lung infections include:

COVID-19: Adults should receive an initial two-dose vaccine series, followed by boosters every 6 to 12 months
Influenza: Adults should receive one dose of the season flu vaccine in the fall
Pneumococcal: The vaccine to prevent pneumonia is typically only needed once under the age of 65. Adults older than 65 may need follow-up immunizations, depending on the vaccine they received.
RSV: This vaccine is approved and recommended for people aged 60 and over. It also can be given to a pregnant person between 32 and 36 weeks of gestation to help prevent RSV in the newborn.

Good Hygiene

Prevent catching cold, flu, and other viruses. practice good hygiene. Try the following tips from the Centers for Disease Control and Prevention:

Wash your hands with soap and water, which removes most respiratory viruses and other germs.
Use a hand sanitizer with at least 60% alcohol when you do not have access to a sink.
Disinfect surfaces using household cleaners or EPA-registered sanitizing spray. If someone in your home is sick, clean more frequently.
Wear face masks in crowded areas, medical offices, and around people who show signs of a respiratory infection.
Keep your distance from anyone who is sick.

Don't Smoke

Smokers have a higher risk of lung infections. Cigarette smoke causes chronic lung inflammation that narrows the air passages, making it more difficult to breathe and clear your lungs.

Over time smoking destroys lung tissue and makes you more susceptible to lung infections and chronic bronchitis.

You should also avoid indoor and outdoor air pollutants that can harm your lungs.

Build Immunity

Keeping your immune system strong can help to prevent lung infections. The CDC recommends the following tips for boosting your immunity:

Avoid excessive drinking: Too much alcohol can weaken the immune system. 
Don't skimp on sleep: Adults need at least 7 hours of sleep a night. Not getting enough can weaken your immune system. 
Eat right: A balanced diet that includes plenty of fruits, vegetables, lean proteins, whole grains, and low-fat dairy can keep your immunity strong. 
Get some exercise: Regular physical activity can benefit the immune system and protect you from viruses.

Lung Infection Complications

A lung infection can be a serious illness by itself, but it can also lead to more health problems—some of which can be serious. The complications of a lung infection can happen soon after a person gets sick (acute) or later (chronic).

Acute

Some of the acute complications of lung infections are breathing problems. For example, viral lung infections can trigger an asthma attack in patients who have asthma.

Lung infections can also cause exacerbations in people with chronic obstructive pulmonary disease (COPD), which can in turn worsen that condition.

Chronic

Some effects of a lung infection don't go away when a person gets better. For example, babies and kids who get bronchiolitis are at an increased risk of having wheezing and asthma later in childhood.

There is also concern that viral lung infections could play a role in a person's risk of getting COPD.

Summary

Lung infections are often caused by viruses and bacteria, like influenza, COVID, and pneumonia. It's also possible to get a lung infection caused by fungi and parasites, but it's less common.

Lung infections can affect different parts of the respiratory tract. They can cause mild to severe symptoms and illness. Some people, like babies, children, older adults, and people with chronic medical conditions, are at a higher risk of getting very sick and having complications from lung infections.

Some complications of lung infections, like breathing problems, can start as soon as a person gets sick and might require medical care. Others, like asthma and COPD, might not come on until later or might last even after a person recovers from a lung infection.

The treatment for lung infections depends on what is causing it and how sick a person is. If you have symptoms of a lung infection, tell your provider. You might be able to treat a lung infection at home with rest, fluids, OTC products, and home remedies. If you need medical treatment like antibiotics, your provider can prescribe them for you.

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