Are Upper Respiratory Infections Contagious? A Doctor Explains What You Need to Know.

Is an upper respiratory infection contagious? Here’s what’s true and what’s false.

“An upper respiratory infection usually affects the upper part of your airways, which is mainly your nose and throat,” explains Kavitha Bagavathy, MD, a pulmonologist at Keck Medicine of USC.  

Because your nose and throat connect to your ears and sinuses, an upper respiratory infection can impact all these areas. 

Upper respiratory infection symptoms 

What upper respiratory infection symptoms can you expect? Common symptoms include: 

• Stuffy or runny nose 
• Sneezing 
• Sore throat 
• Sinus pressure or pain 
• Ear discomfort 
• Postnasal drip that causes coughing 

These symptoms occur because infection causes inflammation in the lining of your nose and throat, leading to increased mucus production. Symptoms can begin within 12 hours of exposure. Most people improve within a week, although some symptoms like a cough may persist longer. 

People with underlying health conditions must be more aware and cautious about infections. If you or a loved one has a compromised immune system, diabetes, asthma or other chronic conditions, you may develop more severe symptoms or bacterial infections more easily. Contact your doctor early on if you develop an upper respiratory infection rather than waiting to see if symptoms improve. Also, check with your health care provider before taking over-the-counter medications, as these might interact with your regular prescriptions.  

Are upper respiratory infections contagious? 

While many worry about catching an upper respiratory infection through coughs or sneezes, Dr. Bagavathy explains that hand contact is the most common transmission route, not talking or sneezing. 

Here’s how transmission typically happens: 

1. An infected person touches their nose or mouth. 
2. The virus stays active on their hands for approximately two hours. 
3. They touch surfaces or shake hands with others. 
4. Those people touch their own face, allowing the virus to enter through the eyes, nose or mouth. 

When are you most contagious? 

You’re most contagious during Day 2 and Day 3 of upper respiratory infection symptoms. However, you can remain contagious for up to two weeks. 

To help prevent spreading an upper respiratory infection: 

• Sneeze or cough into your elbow, not your hands. 
• Consider wearing a mask when sick. It helps contain larger droplets. 
• When wearing a mask, avoid touching it and then touching other things. 
• Stay home during the peak contagious period. 
• Maintain distance from others, especially those with weakened immunity. 
• Avoid shaking hands with others. 

Upper respiratory tract infection treatments 

Most upper respiratory infections (over 98%) are viral and improve on their own within a week. However, in rare cases when bacteria cause the infection, antibiotics are specifically prescribed to target and treat these bacterial cases, Dr. Bagavathy explains. This happens when: 

• Symptoms worsen after seven days 
• Breathing sounds become abnormal 
• X-rays show that the infection has moved to the lungs and is no longer an upper respiratory infection 
• Tests confirm bacteria are present 

For common viral infections, focus on symptom relief: 

• Saline nasal irrigation 
• Rest when needed 
• Staying hydrated 
• Over-the-counter medications to ease symptoms, especially if congestion affects sleep 

Myths about upper respiratory tract infections 

Several misconceptions persist about upper respiratory infections. Dr. Bagavathy dispels two common myths about upper respiratory tract infection symptoms: 

• Green or yellow mucus doesn’t necessarily mean you have a bacterial infection. 
• Cold weather doesn’t increase your risk of an infection. Different viruses are simply more active in different seasons. 

She also offers clarifies these important points about transmission: 

• Using tissues and handkerchiefs lowers the risk of spreading infection.  
• Airplane air circulation hasn’t been shown to increase infection risk. 
• Antibacterial products may not always help reduce risk because most upper respiratory infections are viral, not bacterial. 
• For nasal irrigation, use only saline solution. Essential oils can harm your lungs if inhaled. 
• Even “natural” remedies like herbal teas can interact with medications. 

Finally, contact your health care provider if symptoms worsen after seven days instead of improving, especially if you develop: 

• Difficulty breathing 
• High fever 
• Severe fatigue preventing daily activities 

By knowing about symptoms, how to prevent infections and when to see a doctor, you can better handle upper respiratory infections and protect yourself and others from these common illnesses. 

Topics