Pneumonia – Symptoms and Causes

Pneumonia is an infection and inflammation in one or both lungs which is caused by bacteria, viruses, and fungi.(1)

Due to rhe infection, inflammation occurs in the air sacs of your lungs, which are called alveoli. The alveoli fill with fluid or pus, making it harder to breathe.

Read on to learn more about pneumonia and how it can be treated.

Is pneumonia contagious?

The microbes that cause pneumonia are contagious. So they can spread from person to person.

Both viral and bacterial pneumonia can spread to others through inhalation of airborne droplets from a sneeze or cough of an infected person. You can suffer from these types of pneumonia by coming into contact with surfaces or objects that are contaminated with pneumonia-causing microorganisms such as bacteria and viruses.

You can get fungal pneumonia from the environment. Though, it doesn’t spread from person to person.

Symptoms of pneumonia

Pneumonia symptoms can be mild to very severe. They can include:

Other symptoms can differ according to your age and common health:

  • Children under 5 years old may have rapid breathing or wheezing.
  • Infants may usually have no symptoms, but sometimes they may vomit, lack energy, or have difficulty drinking or eating.
  • Older people may have milder symptoms. They can also show confusion or a lowered body temperature.

Causes of pneumonia

There are various types of infectious agents that can lead to pneumonia.

Bacterial pneumonia

The most common cause of bacterial pneumonia is Streptococcus pneumoniae. Other causes are the following:

Viral pneumonia

Respiratory viruses are usually the cause of pneumonia. Some examples include:

Viral pneumonia is generally milder and can improve in one to three weeks without any treatment.

Fungal pneumonia

Fungi from soil or bird droppings can lead to pneumonia. They usually cause pneumonia in people with weakened immune systems.  Following are the examples of fungi that can cause pneumonia :

Types of pneumonia

Pneumonia can also be categorized according to where or how it was obtained.

Hospital-acquired pneumonia (HAP)

Hospital acquired or nosocomial  bacterial pneumonia is acquired  during a hospital stay. It can be more severe than other types, as the bacteria involved may be more resistant to antibiotics.

Community-acquired pneumonia (CAP)

Community-acquired pneumonia (CAP) refers to pneumonia that’s acquired outside the hospital or medical setting.

Ventilator-associated pneumonia (VAP)

When patients acquired the pneumonia while using a ventilator, it’s called VAP.

Aspiration pneumonia

Aspiration pneumonia occurs when you inhale bacteria into your lungs from food, drink or saliva. This type is more offen occur if you have a swallowing issues or if you’re too sedate or steady from the use of medications, alcohol, or other drugs.

Pneumonia treatment

Your treatment will depend on the type of pneumonia you have, it’s  severity, and your general health.

Prescription medications

Your doctor may recommend a medication to help treat your pneumonia. What you’re recommended will depend on the distinct cause of your pneumonia.

Oral antibiotics can treat most cases of bacterial pneumonia. Always take your complete course of antibiotics, even if your symptoms are relieved. Not completing your course can prevent the infection from clearing, and it may be difficult to treat in the future.

Antibiotic medications can’t treat viral pneumonia. In some cases, your doctor may recommend an antiviral. However, many cases of viral pneumonia clear on their own with a proper home care.

Antifungal medications are used to treat fungal pneumonia. You may have to follow this medication for many weeks to cure the infection.

At-home care

Your doctor may also prescribe over-the-counter (OTC) medication to ease your pain and fever, as required. These may include:

Your doctor may also suggest cough medicine to calm your cough so you can rest. Notice that coughing helps remove fluid from your lungs, so you don’t want to remove it completely.

You can help your recovery and prevent a recurrence by having appropriate rest and drinking lots of fluids.


If your symptoms are very serious or you have other health issues, you may require to be hospitalized. At the hospital, doctors can keep record of your heartbeat, temperature, and breathing. Hospital treatment may be the following :

  • intravenous antibiotics injected into a vein
  • respiratory therapy, which involves providing particular medications directly into the lungs or teaching you to do breathing exercises to increase your oxygenation
  • oxygen therapy to maintain oxygen levels in your bloodstream (received through a nasal tube, face mask, or ventilator, depending on severity)

Pneumonia risk factors

Anyone can suffer from pneumonia, but certain groups are at a higher risk. These groups are :

  • infants from birth to 2 years old
  • people ages 65 years and older
  • people with weakened immune systems because of disease or use of medications, such as steroids or certain cancer drugs
  • people with certain chronic medical conditions, such as asthmacystic fibrosisdiabetes, or heart failure
  • people who’ve recently had a respiratory infection, such as a cold or the flu
  • people who’ve been recently or are currently hospitalized, particularly if they were or are on a ventilator
  • people who’ve had a stroke, have problems swallowing, or have a condition that causes immobility
  • people who smoke, use certain types of drugs, or drink excessive amounts of alcohol
  • people who’ve been exposed to lung irritants, such as air pollutants, fumes, and certain chemicals

Pneumonia prevention

In several cases, pneumonia can be prevented.


The first line of defense against pneumonia is to take vaccine. There are many vaccines that can help prevent pneumonia.

Prevnar 13 and Pneumovax 23

Both of these pneumonia vaccines help protect against pneumonia and meningitis caused by pneumococcal bacteria. Your doctor can tell you which one might be appropriate for you.

Prevnar 13 is operative against 13 types of pneumococcal bacteria. The Centers for Disease Control and Prevention (CDC) recommendsTrusted Source this vaccine for:

  • children below the age of 2 years
  • adults of 65 years or more years of age
  • people between 2 to 64 years of age with chronic conditions that increase their risk for pneumonia

Pneumovax 23 is effective against 23 types of pneumococcal bacteria. The CDC recommendsTrusted Source it for:

  • adults ages 65 years and older
  • adults ages 19 to 64 years who smoke
  • people between 2 and 64 years of age with chronic conditions that increase their risk for pneumonia

Flu vaccine

Pneumonia can usually be a complication of the flu, so make sure to also get an annual flu shot. The CDC recommendsTrusted Source that everyone ages 6 months and older get vaccinated, especially those who may be at risk for flu complications.

Hib vaccine

This vaccine is effective against Haemophilus influenzae type b (Hib), a type of bacteria that can lead to pneumonia and meningitis. The CDC recommendsTrusted Source this vaccine for:

  • all children below the age of 5 years
  • unvaccinated older children or adults who have some specific health conditions
  • people who’ve gotten a bone marrow transplant

According to the National Institutes of Health (NIH)Trusted Source, pneumonia vaccines won’t prevent all cases of this disease. But if you’re vaccinated, you’re probably to get a milder and shorter illness as well as a lowered risk for complications.

Other prevention tips

Along with vaccination, there are other things you can to avoid pneumonia:

  • If you smoke, try to quit. Smoking increase your risk of getting respiratory infections, particularly pneumonia.
  • Regularly wash your hands with soap and water.
  • Cover your coughs and sneezes and quickly dispose used tissues.
  • Follow a healthy lifestyle to strengthen your immune system. Get appropriate rest, take a healthy diet, and do regular exercise.

Getting vaccinated and following additional preventive measures, you can help lower your risk for getting pneumonia. Here are even more prevention tips.

Pneumonia diagnosis

Your doctor will begin by taking your medical history. They’ll ask you questions about when your symptoms first appeared and your health in general.

Then they’ll perform a physical exam which involves listening to your lungs with a stethoscope for any abnormal sounds, such as crackling. Depending on the severity of your symptoms and your risk for complications, your doctor may also perform one or more of these tests:

Chest X-ray

An X-ray helps your doctor to determine signs of inflammation in your chest. If inflammation is present, the X-ray can also help your doctor about its location and extent.

Blood culture

In this test blood sample is taken to confirm an infection.Culturing can also help identify what is the cause behind your condition.

Sputum culture

During a sputum culture, a sample of mucus is collected after you’ve coughed deeply. It’s then sent to a lab for its analysis to recognize the cause of the infection.

Pulse oximetry

pulse oximetry measures the quantity of oxygen in your blood. A sensor placed on one of your fingers can indicate whether your lungs are delivering required oxygen through your bloodstream.

CT scan

CT scans give a clearer and more detailed picture of your lungs.

Fluid sample

If your doctor suspects there’s fluid in the pleural space of your chest, they may take a fluid sample with the help of a needle placed between your ribs. This test can help recognize the cause of your infection.


bronchoscopy looks into the airways in your lungs. This is done by using a camera on the end of a flexible tube that’s gently guided down your throat and into your lungs. Your doctor may perform this test if your early symptoms are severe, or if you’re hospitalized and not responding well to antibiotic treatment.

Walking pneumonia

Walking pneumonia is a milder form of pneumonia. People having walking pneumonia may not even know they have pneumonia, because their symptoms may feel similar to a mild respiratory infection than pneumonia.

The symptoms of walking pneumonia can include:

  • mild fever
  • dry cough lasting more than a week
  • chills
  • breathlessness or dyspnea
  • chest pain
  • lowered appetite

Moreover, viruses and bacteria, like Streptococcus pneumoniae or Haemophilus influenzae, usually cause pneumonia. Although, in walking pneumonia, bacteria like Mycoplasma pneumoniaeChlamydophilia pneumoniae, and Legionella pneumoniae lead to the condition.

In spite of being milder, walking pneumonia may need a longer duration for recovery than pneumonia.

Is pneumonia a virus?

Several different types of infectious agents or microbes can lead to pneumonia. Viruses are just one of them. The others agents are bacteria and fungi.

Following are the some examples of viral infections that can cause pneumonia:

Although the symptoms of viral and bacterial pneumonia are very similar, cases of viral pneumonia are usually milder than those of bacterial pneumonia. According to the NIH, people having viral pneumonia have a risk for developing bacterial pneumonia.

One major difference between viral and bacterial pneumonia is treatment. Antibiotics are not effective for viral infections. Many cases of viral pneumonia may be treated with at-home care, although antivirals may sometimes be recommended.

Pneumonia vs. bronchitis

Pneumonia and bronchitis are two different conditions. Pneumonia is an inflammation of the air sacs in your lungs. While bronchitis is the inflammation of your bronchial tubes. These are the tubes that carry air to your lungs.

Infections cause both pneumonia and acute bronchitis. Additionally, continuous or chronic bronchitis can occur from inhaling pollutants, such as cigarette smoke.

A viral or bacterial infection can cause a bout of acute bronchitis. If the condition left untreated, it can develop into pneumonia. Sometimes it’s difficult to tell if this has happened. The symptoms of bronchitis and pneumonia appears very similar.

If you have bronchitis, it’s necessary to get it treated to prevent developing pneumonia.

Pneumonia in kids

Pneumonia can be a quite common childhood condition. Researchers estimate there are 120 million cases of pediatric pneumonia all over the world every year.

The causes of childhood pneumonia can differ by age. For example, pneumonia due to respiratory viruses, Streptococcus pneumoniae, and Haemophilus influenzae is more common in children below the 5 years of age.

Pneumonia due to Mycoplasma pneumoniae is frequently seen in children between the age of 5 and 13 years. Mycoplasma pneumoniae is one of the causes of walking pneumonia. It’s a milder form of pneumonia.

Talk to your pediatrician if you notice your child:

  • is having difficulty breathing
  • lacks energy
  • has changes in appetite

Pneumonia can become threatening fastly, especially in young children. Here’s how to avoid complications.

Pneumonia home remedies

However, home remedies don’t actually treat pneumonia, there are some steps you can do to help relieve symptoms.

Coughing is one of the most common symptoms of pneumonia. Natural ways to ease a cough involve gargling salt water or drinking peppermint tea.

Things like OTC pain medication and cool compresses can work to ease a fever. Drinking warm water or taking a good warm bowl of soup can help with chills. Here are six more home remedies to try.

Although home remedies can help alleviate symptoms, it’s necessary to regularly follow your treatment plan. Take any prescribed medications as directed.

Pneumonia recovery

Most people respond to treatment and recover from pneumonia. Like your treatment, your recovery time will depend on the type of pneumonia you have, its severity, and your general health condition.

A younger person may recover in a week after treatment. Others may take longer time to recover and may have persisting fatigue. If your symptoms are severe, your recovery may take several weeks.

Consider taking these steps to aid in your recovery and help prevent complications:

  • Follow the treatment plan strictly, your doctor has developed and take all medications as per instruction.
  • Make sure to get enough rest to help your body fight the infection.
  • Drink lots of fluids.
  • Ask your doctor when you should schedule a follow-up appointment. They may want to perform another chest X-ray to ensure your infection has cleared.

Pneumonia complications

Pneumonia may lead to complications particularly in people with weakened immune systems or chronic conditions, such as diabetes.

Worsened chronic conditions

If you have certain preexisting health conditions, pneumonia could make them more severe. These conditions include congestive heart failure and emphysema. For certain people, pneumonia increases their risk for getting a heart attack.


Bacteria from the pneumonia infection may spread to your bloodstream. This can cause threatening low blood pressure, septic shock, and in few cases, organ failure.

Lung abscesses

These are cavities in the lungs filled with pus. Antibiotics can treat them. Sometimes they may need drainage or surgery to remove the pus.

Impaired breathing

You may have difficulty getting enough oxygen when you breathe. You may require to use a ventilator.

Acute respiratory distress syndrome

It is a severe form of respiratory failure. It needs urgent treatment.

Pleural effusion

If your pneumonia isn’t treated, fluid may develop around your lungs in your pleura, called pleural effusion. The pleura are thin membranes that surrounds the outside of your lungs and the inside of your rib cage. The fluid may become infected and require to be drained.


In some cases, pneumonia can be fatal. According to the CDC, more than 49,000 deaths occured in the United States from pneumonia in 2017.

Is pneumonia curable?

Various infectious agents cause pneumonia. With proper identification and treatment, many cases of pneumonia can be cured without complications.

For bacterial infections, quitting your antibiotics early can cause the infection to not clear Completely. This means your pneumonia could come back. Stopping antibiotics early can also lead to antibiotic resistance. Antibiotic-resistant infections are harder to treat.

Viral pneumonia usually settle down in one to three weeks with at-home treatment. In some cases, you may require antivirals. Antifungal medications treat fungal pneumonia and may need a prolonged period of treatment.

Pneumonia stages

Pneumonia may be categorized on the basis of the area of the lungs it’s affecting:


Bronchopneumonia can affect areas throughout both of your lungs. It’s usually localized close to or around your bronchi. These are the tubes that lead from your trachea to your lungs.

Lobar pneumonia

Lobar pneumonia affects one or more lobes of your lungs. Right lung have three lobes and left lung have two lobes, which are defined sections of the lung.

Lobar pneumonia can be further divided into four stages on the basis it’s progression.

  1. Congestion. Lung tissue appears heavy and congested. Fluid containing infectious microbes has accumulated in the air sacs.
  2. Red hepatization. Red bloods cells and immune cells have entered into the fluid. Due to these cells, lungs appear red and solid in appearance.
  3. Gray hepatization. The red blood cells have started to break down while immune cells remain. The breakdown of red blood cells leads to change in color, from red to gray.
  4. Resolution. Immune cells have started to clear the infection. A productive cough helps remove remaining fluid from the lungs.

Pneumonia pregnancy

Pneumonia that occurs during pregnancy is called maternal pneumonia. Pregnant women have higher risk of developing conditions like pneumonia. This occurs because of natural suppression of the immune system that occurs when you’re pregnant.

The symptoms of pneumonia don’t vary by trimester. Though, you may notice some of them more later on in your pregnancy due to other discomforts you may be experiencing.

If you’re pregnant, talk to your doctor immediately when you start experiencing symptoms of pneumonia. Maternal pneumonia can cause a variety of complications, such as premature birth and low birth weight.

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