Upper Respiratory Tract Infection (URI): Causes, Symptoms & Treatment

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  • 0:04 Upper Respiratory…
  • 1:08 Causes
  • 2:48 Signs & Symptoms
  • 3:19 Treatment
  • 4:17 Lesson Summary
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Lesson Transcript
Instructor: Erin Lewis
Upper respiratory tract infections (URIs) are one of the most common conditions seen by primary care providers. Learn more about the causes, signs and symptoms, and the treatment of this common condition. Complete a quiz to evaluate your understanding.

Upper Respiratory Tract Infections

How many of us have woken up on Monday morning with a runny nose, cough, and feeling absolutely exhausted before you have to go to work? You tell yourself you're just exhausted from the weekend. You tough it out through the day but come home feeling worse. You visit your doctor and find out you have a respiratory infection.

First, let's talk about your respiratory tract. Your respiratory tract is a body system that allows oxygen into your body while releasing the waste product carbon dioxide. Basically, it allows the good stuff that keeps us alive to come in while getting rid of the bad stuff, or the waste. As with every part of the body, the respiratory tract can become infected when germs find their way into these essential organs.

An upper respiratory tract infection, or URI, results when infectious agents enter the nose or mouth and travel into the upper part of the respiratory system, including the nose, trachea (breathing tube), and vocal cords. If this infection continues to travel, it can result in an infection of the lungs or a lower respiratory tract infection.

Causes of URIs

Now you have left your doctor's appointment with the diagnosis of URI, and you realize that you were around someone with a cold earlier this week. You are wondering if there's a connection while also feeling frustrated at that person for exposing you.

URIs can be caused by a variety of fairly common things that most of us don't even realize that we're exposed to. On a daily basis, we breathe in various agents, such as bacteria, viruses, and fungi, all of which are microscopic organisms that can result in infections in our body. Our immune system naturally kills most of these agents off, but sometimes when our body is under stress, we fail to completely fight the infection, which results in illness.

Microscopic view of bacteria

Think of all of the people who have coughed or sneezed in your presence over the past week. When a person coughs or sneezes near us, the germs in their lungs reach the air, leaving us susceptible to inhaling them. Often, it's viruses that are released, which are the most common cause of URI. If our immune system is unable to fight these germs, or our nasal hairs and mucous fail to catch them, the bacteria or virus attach to our upper airways and reproduce, resulting in an URI.

Now think of the last time you touched a doorknob, keys, money, or a countertop. It was probably within the past hour, if not less. Another way we contract URI is through direct contact with contaminated objects. For example, if a person has a cold and they wipe their nose, then touch a doorknob, each person who later touches that doorknob will be exposed to the infectious agent. If each of those people then touch their nose or mouth, they have a chance of then developing the same infection.

Signs & Symptoms of URIs

Let's move on to the various symptoms that caused you to visit the doctor. Signs and symptoms of URI include runny nose, low-grade fever, cough (either dry or wet), sore throat, and fatigue. Most people experience cold-like symptoms, which can be self-limiting but not completely debilitating like the flu. If the infection is bacterial, the person will most likely have nasty colored green or grey colored mucous. If the infection is viral, the mucous is usually clear or yellow.

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