Lower Respiratory Tract Infections, Illnesses and Diseases

Respiratory infections cause respiratory illnesses and infectious diseases that affect your upper and lower respiratory tracts. Thus, depending on the source, you will have an upper respiratory tract infection (URTI) or a lower respiratory tract infection (LRTI). 

What is the Lower Respiratory Tract?

mage of the lower respiratory tract (i.e., lungs and airways)

Your lower respiratory tract includes your lungs, bronchioles, and airways. Additionally, certain viral or bacterial infections affect one or more of these structures. These are lower respiratory tract infections (LRTI), illnesses, and infectious diseases caused by respiratory infections.


Your lungs contain organisms that defend you against infections. But, viral or bacterial infections disturb these organisms and cause infections. Thus, pneumonia is an infection of your lungs. Pneumonia infections can affect part of your lungs, an entire lobe, or just your airways. 

There are two kinds of pneumonia ⎯ bacterial and viral. As their name suggests, bacterial infections cause bacterial pneumonia. In contrast, viral infections cause viral pneumonia. Both types of pneumonia are infections in your lower respiratory tract. Additionally, there are three ways people acquire pneumonia. 

  • Hospital-acquired pneumonia (HAP)
  • Community-acquired pneumonia (CAP)
  • Ventilator-associated pneumonia (VAP)

Symptoms of Pneumonia

Pneumonia can have different causes and sources. But, for the most part, the symptoms are the same.

  • Fever with chills
  • Labored or crackled breathing
  • Bloody or watery sputum
  • Loss of appetite
  • Chest or muscle pain

Diagnosing Pneumonia

Your healthcare provider will take different steps to diagnose you with pneumonia. In general, these steps include:

Chest X-Ray

Chest x-rays are the best way to diagnose pneumonia. They provide an image of your lungs, which allows your healthcare provider to determine the location of your infection.


Your healthcare provider may do additional tests and evaluations to help determine the cause of your infection. These include blood tests, samples, and evaluating markers of inflammation and bacterial infections.

Managing and Treating Pneumonia

There is no treatment for viral pneumonia. However, healthcare providers may prescribe an antiviral medication if they suspect the cause is the flu virus. Commonly, they manage and treat your symptoms, replenish your fluids, provide oxygen therapy, and use antibiotics to treat bacterial infections.


Bronchitis is a common respiratory illness caused by inflammation in your lower respiratory tract, specifically your windpipe and airways. Bacterial or viral infections cause bronchitis. However, viral infections cause most cases of acute bronchitis. Acute bronchitis causes mild symptoms that resolve within two weeks. Most infections occur during the colder months, like fall and winter.

Symptoms of Bronchitis

  • Productive cough
  • Wheeze
  • Labored breathing
  • Fever
  • Sore throat

Diagnosing Bronchitis

Your healthcare provider takes different steps to diagnose your bronchitis and rule out other conditions like pneumonia. To illustrate, these steps include:

Lung Exam

Your healthcare provider assesses your lungs for any abnormalities, such as crackles and wheezes.

Chest X-Ray

A chest x-ray is not necessary to diagnose bronchitis. But, your healthcare provider may perform a chest x-ray to rule out pneumonia.

Other Exams

Breathing tests give information on your respiratory system. Additionally, a blood test will determine the presence of an infection.

Managing and Treating Bronchitis

Usually, healthcare providers prescribe different medications to manage and treat your symptoms. For instance, they may prescribe steroids to address the inflammation and beta-agonists for your wheeze. Over-the-counter medications can also help to relieve your symptoms, like your cough and sore throat.


Tuberculosis (TB) is a chronic infectious disease resulting from a bacterial infection in your lower respiratory tract. Thus, it often affects your lungs. However, TB infections can affect other systems and organs, like your brain, intestines, kidneys, and spine.

Symptoms of TB

TB symptoms depend on the location of the bacterial infection. But, most people experience one or more of these symptoms.

  • Chronic cough
  • Chest pain
  • Weakness and fatigue
  • Fever
  • Unexplained weight loss

Diagnosing TB

Diagnosing TB is not a simple process. To illustrate, healthcare providers must use a combination of assessing your clinical signs and symptoms and investigation to give you a diagnosis. The process often includes:

Sputum Samples

When you have an infection, you produce sputum. Sputum is a thick mucus from your respiratory tract. So, your healthcare provider examines sputum samples to determine the presence of bacteria that causes TB.

Chest X-Rays

Usually, chest x-rays help your healthcare provider identify problems with your lungs. But, you can have TB that’s undetected from a chest x-ray.

Nucleic Acid Amplification (NAA)

Healthcare providers use NAA tests to determine the presence of TB-causing bacteria.

Managing and Treating TB

Vaccines help to prevent the initial infection. However, they don’t protect you from all strains of TB. TB infections persist. But, that doesn’t mean that it is impossible to cure. Antituberculosis drugs are the first line of treatment for TB. However, some strains are drug-resistant. Thus, your healthcare provider may prescribe multiple therapies to treat your TB infection, such as less common TB drugs. Additionally, your healthcare provider may prescribe antibiotics for drug-resistant TB. Antibiotics limit the number of bacteria in your lungs.