Lung Infection Symptoms – When Do You See a Doctor?

Lung infection and its Causes

Cough due to lung infection

A lung infection develops when bacteria or viruses invade the lining of your lungs and begin to grow there. When this occurs in your lungs, you’ll become ill. 

You’ll become infected when you breathe in the bacteria or virus from an infected person nearby, who coughs or sneezes. Your illness may have resulted from a range of possible causes. You may have been struck down by a bacterial, virus, or a fungal lung infection.

When your lungs are invaded by foreign bacteria and viruses, air sacs in your lungs become filled with pus and liquid. These air sacs are very important structures that aid your breathing. 

As you breathe in air containing oxygen, the air usually passes through your windpipe and bronchi. The air eventually reaches the air sacs in your lungs. These air sacs look like grapes, and they provide a large surface area where oxygen and carbon dioxide are exchanged in your lungs. 

When the air sacs in your lungs become filled with liquid and pus, you’ll have difficulty breathing. You’ll start coughing, and you’ll experience some chest pain. 

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How is Lung Infection Diagnosed?

Blood work to detect lung infection

When you’re diagnosed, your doctor will tell you what type of lung infection you have. Tests that your doctor may use to determine what you have include:

History of your symptoms: Your doctor will ask you about the symptoms that you’re having. They will also obtain other relevant medical histories from you.

Physical examination: Your doctor will listen to your lungs and conduct other physical examinations that will help them in their determination of what you may have.

Oxygen levels: Your blood oxygen levels will be checked using a pulse oximeter. This is a non-invasive,  painless monitor that is placed on your finger. 

If you frequently have bronchitis or congestion, it is advisable that you keep a pulse oximeter at home. You should regularly check your oxygen saturation at home, and notify your doctor if it is low. 

The pulse oximeter measures your heart rate as well. You can get a good one for less than fifty dollars.

Sputum analysis will be used to determine which microorganism is causing your lung infection.

Chest X-rays will be used to confirm if you have pneumonia.

Blood tests: Blood tests will be used to measure the white blood cell count in your blood. This will help your doctor confirm that you have an infection. 

They will also be able to determine how severe your infection is. Additionally, your doctor will determine whether your infection was caused by bacteria, virus, or fungus.

Blood cultures will be used to find out which microorganism from your lungs has spread into your bloodstream.

ABG (arterial blood gas) blood test is used to find out an accurate reading of your body’s oxygen and carbon dioxide levels, among other factors.

CT scan of your chest will usually provide your doctor with more details than the chest X-ray does.

Bronchoscopy is an invasive procedure done by a pulmonary specialist. You will be under anesthetic, then a thin, flexible, and lighted tube called a bronchoscope will be passed down into your lungs. 

This examination lets your doctor determine what parts of your airways and lungs are affected.

Types of lung infections

Some people think that asthma is a lung infection. However, it is not caused by an infection. Asthma is a lung disease that makes it harder to move air in and out of your lungs. For how to manage asthma symptoms and prevent future attacks, check here.

The three main types of lung infections are:

  • Bronchitis
  • Pneumonia
  • Bronchiolitis.  


Woman ill with bronchitis

Bronchitis is a lung infection that causes inflammation of the lining of your bronchial tubes. The bronchial tubes carry oxygen into your lungs, and carbon dioxide out of your lungs. 

If you have bronchitis, you may cough up thick mucus. The mucus may be discolored. This infection often occurs after you’ve had a common cold or some other respiratory infection. (1). Your bronchitis may be acute or chronic. 

Lung infection symptoms associated with bronchitis include: (1, 2)

  • A cough that produces clear, white, yellow, or greenish mucus (sputum).
  • Fatigue
  • Slight fever and chills
  • Wheezing
  • Shortness of breath
  • Sore throat
  • Headache
  • Chest discomfort
  • Body aches
  • Sore ribs and sore stomach due to excessive coughing. 

Acute bronchitis 

This is a type of lung infection that is also known as a chest cold. It is common and is caused by viruses. It is caused by the same viruses that cause your common cold or the flu.

This type of lung infection doesn’t usually have lasting effects on you. When you get it, you will get better within 7-10 days. The cough may persist for some weeks though.

If you keep having bouts of bronchitis, this is not a good sign. You should have yourself checked by your doctor because you may have developed chronic bronchitis.

Chronic bronchitis 

This is a more serious medical condition. It is one of the conditions included in chronic obstructive pulmonary diseases (COPD).  

Cigarette smoking is the most common cause of chronic bronchitis. Other reasons why you may have chronic bronchitis are:

  • Toxic gases in your environment or your workplace
  • Air pollution
  • Dust

You should suspect that you have chronic bronchitis if you have a productive cough that lasts for at least three months. If you have recurring bouts of this type of cough occurring for at least two consecutive years, you may have chronic bronchitis. 

If you have chronic bronchitis, there may also be periods when you’ll have symptoms of acute bronchitis. When this happens, your cough and other symptoms will likely get worse.

When do you see a doctor?

Your lung infection can be serious if it remains untreated. You should see a doctor if your cough lasts more than three weeks, or if you’re having trouble breathing.

For your infant child

Baby sick with lung infection

You should see a pediatrician if your infant is:

  • 0 – 3 months with a fever and the temperature is above 100.4 F (38 C)
  • 3 – 6 months with a fever that’s above 102 F (38.9 C)
  • 6 – 12 months with a fever over 102 F (38.9 C)

For children

You should see your child’s pediatrician if your child:

  • Has a fever and the temperature is above 102.2 F (38.9 C)
  • Has had a fever which has lasted for more than three days
  • Vomits repeatedly, is irritable, or has a severe headache
  • Has recently visited a developing country

For adults

You should see your doctor if your cough:

  • Produces discolored mucus
  • Produces blood
  • Causes wheezing
  • Causes shortness of breath
  • Prevents you from sleeping
  • Is accompanied by a fever and your temperature is higher than 103.4 F (39 C), especially if your fever has lasted for more than three days
  • Lasts for more than three weeks


This is a type of lung infection that can be life-threatening. Pneumonia may be caused by bacterial, viral, or fungal infection. It causes your lungs to become inflamed. The tiny air sacs in your lungs become filled up with fluid and pus.

Pneumonia is the leading cause of death from infection in children younger than 5 years of age. It occurs in both young and healthy individuals.  

You’re at higher risk to have pneumonia if:

  • You are very young
  • You’re an older adult
  • You have underlying health problems
  • There’s impairment in your immune system.

COVID-19 and Pneumonia

Incidentally, the main symptoms of COVID-19 are fever and a persistent cough. If you’re not sure if you have a lung infection or COVID-19, consult your doctor.

If you suspect that you have COVID-19, do not treat yourself with medicines like famotidine as some people have been known to do. Confirm your symptoms with your doctor to know the appropriate steps needed for your treatment.

Common symptoms of lung infection

The first symptoms of lung infection associated with pneumonia usually resemble those of a cold or flu. Later, you will develop a cough, fever, chills, and cough with sputum. 

Fever due to lung infection

Your symptoms may vary depending on the type of pneumonia you have, and other underlying conditions.

Common pneumonia symptoms include:

  • Fever 
  • Shaking chills
  • Cough
  • Chest pain which worsens when you take a deep breath
  • Rusty or green phlegm or sputum which you’ll cough up from your lungs
  • Fatigue and weakness
  • Fast heart rate
  • Fast breathing and shortness of breath
  • Nausea and vomiting
  • Diarrhea
  • Sweating 
  • Muscle pain 
  • Purplish skin color from poor oxygenation


Staying hydrated relieves lung infection

Pneumonia lung infection treatment depends on the type and severity of your illness. 

  • It is important that you get a lot of rest and drink plenty of fluids. 
  • If you’re well-hydrated, this will help to thin out thick phlegm and mucus. You can then easily cough it up.
  • Your doctor may prescribe over-the-counter (OTC) medications to help manage the symptoms of your lung infection. These include treatments for reducing fever, reducing aches and pains, and suppressing coughs.
  • Lung infection antibiotics are used to treat your pneumonia if it was caused by bacteria.
  • If your infection was caused by a virus, you will not be treated with an antibiotic. You will be treated with rest and plenty of fluids. However, if you have influenza, you will be treated with antiviral medications.
  • For fungal lung infection, you’ll be treated with antifungal medications. 
  • You may also use a vaporizer or humidifier to help you breathe better. If you have breathing problems of any sort, you’ll need a humidifier in your room. A good one costs less than $50.
  • You may be hospitalized for lung infection caused by pneumonia. The reason may be that your symptoms are really bad, or your immune system is weak.

Pneumonia in Children

Child ill from bronchitis

When your child develops lung infection due to pneumonia, it is usually due to a virus. Sometimes, your child’s immune system may be able to protect them from pneumonia. 

Symptoms associated with pneumonia in children include:

  • Coughing
  • Difficulty breathing 
  • Fever
  • Not feeding properly
  • Dehydration
  • Irritability


This is a common lung infection that occurs in babies under six months of age. It can also occur in babies that are up to 12 months old. Bronchiolitis is caused by a virus, and affects the small breathing tubes in your baby’s lungs.

Bronchiolitis usually starts as a winter cold in your baby. After a day or two, your baby will begin to cough and his/her breathing will become wheezy. 

Your baby’s illness will usually last for about three to five days. However, the cough may last for up to two to three weeks. 

If your baby is premature, has heart disease or major birth defects, he/she has a higher risk of contracting severe bronchiolitis.

The symptoms of bronchiolitis resemble those of asthma, and they include:

  • Cough
  • Wheezing
  • Difficulty breathing
  • Rapid breathing
  • Flaring of nostrils

When do you seek medical help?

  • If your baby’s symptoms are persistent, you should seek medical advice
  • See a doctor if your baby’s breathing becomes rapid or irregular or they refuse food and drink
  • If your baby turns blue, is tired, pale, sweaty and irritable

Treatment for bronchiolitis

Because bronchiolitis is a viral infection, medications such as antibiotics are not helpful in its treatment. Bronchiolitis is treated like other viral infections. 

The following are measures you should take to make your child feel better if they have bronchiolitis:

  • Let your baby rest as much as possible.
  • Give your baby paracetamol that is appropriate for his/her age. Give the medication as often as recommended. You should follow the dosage requirements that are appropriate for your baby’s age. 
  • Offer your baby small amounts of fluids regularly, more often than usual.
  • When your baby is ill, you should avoid smoking around him/her. If you do, this will make their symptoms worse.

If your baby becomes very distressed and isn’t feeding well, you should have them admitted to the hospital. Your child will be observed closely and will be given intravenous fluid if he/she is dehydrated. 

Your child may receive supplemental oxygen. This is important if their oxygen saturation is low and they’re having difficulty breathing. 

How Can You Prevent Lung Infection From Occurring?

You may prevent pneumonia by taking the vaccine made to protect you against infection. The two different vaccines that are available are Prevnar and Pneumovax.


You should have had the Prevnar vaccine as part of your scheduled immunizations when you were an infant. The following is the recommended Prevnar vaccine protocol:

  • Kids under 2 years of age.
  • Adults over the age of 65
  • Anyone between the ages of 2 and 64 who have certain medical conditions.


You should take the Pneumovax vaccine if you’re a kids or an adult. Pneumovax is for those who’re at increased risk of developing lung infections caused by pneumonia. If you’re an older adult, this vaccine may not completely protect you from pneumonia.

You should take this vaccine if you fall within the following category of people:

  • If you have diabetes 
  • You’re 65 years or older
  • You’ve had your spleen removed
  • You have chronic lung, heart, or kidney disease
  • You consume large amounts of alcohol, or who smoke.

Is lung infection Contagious?

Acute bronchitis is usually contagious. If you have this lung infection, you may spread the contagious viruses to someone else.

You spread acute bronchitis through your droplets. You produce the droplets when you cough, sneeze, or talk. When someone nearby inhales the droplets, they may become infected. 

When you touch an object, you may also spread the viruses through someone’s contact with the infected object. This happens when the person touches something with the virus on it and then touches their mouth, eyes, or nose. 

To avoid your risk of contracting the virus that causes bronchitis, you should:

  • Wash your hand frequently, or use an alcohol-based hand sanitizer
  • Avoid touching your eyes, nose, and mouth
  • Avoid close contact with anyone who is ill with the flu or any other respiratory illness
  • Have a flu shot every year.

Lung infection caused by pneumonia is also contagious. You can pass the bacteria and viruses on through coughing and sneezing. You can also spread it through shared objects when you touch them. 

Bronchiolitis is contagious as well. You should avoid letting your baby come in contact with other children in the first few days that your child is ill. Do not take your sick child to a babysitter or a daycare center.

Read also: How to Effectively Manage Asthma Symptoms at Home

23 thoughts on “Lung Infection Symptoms – When Do You See a Doctor?

  1. Generally I do not read post on blogs, however I would like to say that this write-up very pressured me to try and do so! Your writing style has been surprised me. Thanks, quite great article. Max Brent Attlee

  2. This is a really important post, especially with the pandemic. Thanks for all of the in depth information – the perfect article in these crazy times

  3. I’m glad you got over the pneumonia and bronchitis. They can be bothersome.
    Thanks for your feedback, and for sharing your experience.

  4. I’m well aware of these lung issues because as an asmatic, I used to get pneumonia and bronchitis with annoying regularity.

  5. This post is amazing, so much information in depth and how to diagnose, treat and prevent lung infection

  6. Thanks for all of the in depth information – the perfect article in these crazy times.

  7. It’s certainly timely to be writing about lung ailments right now. We have our pulse oximeter handy!

  8. This is a really important post, especially with the pandemic. It’s important to get checked out and identify symptoms.

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