The Flu vs Bronchitis: How to Tell the Difference

You began feeling tired and achy late in the day. By bedtime, you were nursing a sore throat, a persistent cough, and a low-grade fever. You wondered whether you had caught a bad cold or the flu — or if you were coming down with something else altogether. 

As infectious disease experts who provide prompt care for a full scope of acute illnesses, the team at American River Urgent Care in Orangevale, California, sees patients with respiratory infections almost every day. 

Given that many respiratory infections share a similar set of symptoms, it’s not surprising that most people aren’t sure which illness they’ve contracted until they head to the doctor.

Learn how the seasonal flu differs from acute bronchitis, and find out why, no matter what you think you have, it’s usually a good idea to seek a proper diagnosis. 

What is the seasonal flu? 

Millions of people catch the seasonal flu, or influenza, every year in the United States. This common and highly contagious respiratory infection can range in severity from mild to severe or even life-threatening. Most people recover from the flu in a week to 10 days.

Underlying cause

The flu is caused by influenza viruses (type A or type B) that spread from person to person via microscopic respiratory droplets. When someone who’s ill with the flu talks, laughs, coughs, or sneezes, these contaminated droplets can land on nearby people and surfaces. 

Healthy people contract the flu when the virus gets inside their nose, mouth, or eyes, usually through airborne droplets. It’s also possible to transfer the virus from your hands to your nose, mouth, or eyes after touching a dirty surface. 

Main flu symptoms

The onset of flu symptoms is often swift and intense — many people go from feeling perfectly fine to feeling extremely tired, weak, achy, and feverish in a few short hours. When you have the flu, you may experience some or all of these symptoms:

• Excessive fatigue 
• Chills; feeling feverish
• Muscle or body aches
• Dry cough; chest pain 
• Persistent headaches

While many people also come down with a temperature that lasts three or four days, the flu doesn’t always come with a fever. A sore throat and a stuffy or runny nose are other possible — but less common — flu symptoms.

What is acute bronchitis? 

Acute bronchitis occurs when your airways (bronchi) become inflamed and produce mucus. Also referred to as a chest cold, this cough-inducing respiratory infection is typically mild, usually improves in less than two weeks, and eventually goes away on its own. 

Underlying cause

Most cases of acute bronchitis are caused by a lingering respiratory infection, such as a cold or the flu. In such cases, it’s considered a complication of the virus which caused the initial illness: first it affects your nose, sinuses, and throat, then it spreads down into your lungs and affects your airways. 

Sometimes, acute bronchitis is caused by a bacterial infection. It’s also possible to have viral and bacterial bronchitis at the same time. Environmental irritants like smoke can trigger acute bronchitis as well.  

Main bronchitis symptoms

Because the symptoms of acute bronchitis typically arrive on the heels of another respiratory illness, many people initially believe that their existing cold or flu infection has simply taken a turn for the worse.

But bronchitis is a separate condition with its own unique set of symptoms, most of which are a product of airway inflammation and constriction. Signs of acute bronchitis include:  

• Cough (dry, then productive)
• Chest or upper back soreness 
• Shortness of breath; wheezing
• Mild headache or body aches
• Mild low-grade fever; fatigue

Acute bronchitis typically begins with a dry, nagging cough triggered by irritated airways. This persistent cough often becomes wet, or productive, when the irritated bronchi start producing mucus. It usually persists several weeks longer than other bronchitis symptoms. 

The flu vs bronchitis

The flu typically comes on strong, causing excessive fatigue, weakness, chills, and body aches that improve gradually. For all its similarities, acute bronchitis is mainly defined by a nagging, persistent cough that emerges more gradually and changes over time. 

Given that bronchitis is a common complication of influenza, however, it’s entirely possible to come down with the flu and wind up with a lingering case of acute bronchitis. 

Whenever you develop a major respiratory infection, it’s important to seek a proper diagnosis — no matter what you think you have. Just as treatment options can vary from one respiratory illness to the next, complication risks can vary from one person to the next. 

If you’ve been feeling under the weather, the team at American River Urgent Care can help. Call 916-287-8569 or click online to book a same-day visit at your convenience, or simply stop in any time during our normal business hours.