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Know Why Respiratory Tract Infection is Common in Winter

Verified By Apollo General Surgeon February 6, 2023 894 0
Know Why Respiratory Tract Infection is Common in Winter
Know Why Respiratory Tract Infection is Common in Winter


As the temperatures slowly dip, you start getting out  your blankets, sweaters, socks, and warmers from your closet. Winters are usually synonymous with staying under a warm blanket, drinking a hot cup of coffee or tea, and wearing your warmest clothes. But it also sees many of us getting infected with colds, flu, and other respiratory tract infections. 

When we nurse ourselves back to health, we also wonder why respiratory tract infection is common in winter. The blog provides an answer to the exact question.  

What are the Various Reasons For An Increase In Respiratory Tract Infection Cases In Winter?

Experts have associated the weather with a higher incidence of upper respiratory infection because of increased respiratory viruses. Also, your susceptibility to respiratory viruses increases when the temperatures and humidity decrease. It is backed up by a recent study that shows that cold temperatures result in a decline in the immune system due to the cells in the nasal cavity viruses. 

Experts also believe that there are other reasons, such as the following:

Access to viruses is the nose

Studies have found that extracellular vesicles, membrane-bound particles released by cells that protect the nasal cavity, are a component of the immune response against respiratory viruses. EVs primarily carry DNA, RNA, and proteins and release most cell types. They also prevent viruses from binding or transmitting to uninfected cells and modulate their immune response in the nose. A study showed that winter-like temperatures decreased the nasal cavity’s temperature, weakening the immune response.

Relationship between cooler temperature and immune response

In the past, studies have suggested that upper respiratory infections are common in colder seasons due to an increase in the spread of upper respiratory viruses because of  a change in temperature, humidity, and human behavior, including spending time indoors. This is backed by recent studies suggesting cold temperatures reduce the immune system’s response to viruses, resulting in a higher risk of infections. The nasal cavity is more sensitive to ambient temperature changes than other body parts, including the lungs. Studies have also indicated that rhinoviruses are the most common cause of upper respiratory infections. These viruses can replicate efficiently in lower temperatures in the nasal cavity than in higher temperatures. Today, experts are conducting continuous research to find out how changes in the temperature can lower the immune system response and increase the risk of respiratory tract infections. 

Extracellular vesicles play a vital role

The mucous membrane in the nasal cavity secretes mucus. It is the first layer of protection against inhaled respiratory microbes and is critical in protecting against infection. The mucus membrane stops the entry of infectious microbes and secretes molecules with antimicrobial properties in the mucus. The nasal epithelial cells in the mucous membrane also send  receptors (TLRs)that can activate the innate immune response. The TLRs recognize infected microbes and immediately start the production of immune proteins. Research indicates that the EVs carrying proteins bind and neutralize microbes that enhance the immune response. Sometimes, these EVs fail to stop the infected microbe from entering. Thus, increasing the risk of infection.

Weather conditions

With suitable conditions, viruses like the flu viruses thrive longer at colder temperatures. Temperature, humidity, and closer proximity to people increase the chances of infection. In tropical regions, the flu season is associated with rainy seasons. Also, the lack of sunlight increases the risk of respiratory tract infection.

What are the other ways cold weather affects the immune system?

Experts suggest that cold weather can adversely affect your immune response, resulting in the body struggling to fight off infections. Cold weather also affects the immune system in the following ways:

  1. Decreased vitamin D levels: During the winters, as people are less exposed to the sun, they receive less vitamin D. Vitamin D is vital for maintaining the immune system. 
  2. The lower temperature lowers the immune response: Research conducted on rats found that the mice exposed to viruses during lower temperatures had a decreased immune response to fight off the rhinovirus. 
  3. Narrowing of blood vessels: With cold and dry air, the blood vessels in the upper respiratory tract narrow to preserve heat, preventing the white blood cells from reaching the mucous membrane resulting in a less efficient  immune system. 

How to prevent yourself from getting infected?

The following are some of the preventive steps to reduce the risk of infection:

  1. CDC recommends constantly washing the hands with soap and water for 20 seconds. Also, avoid touching your face, eyes, mouth, and nose with dirty and unwashed hands. 
  2. Stay away from people who are constantly sneezing and coughing. Regularly disinfecting frequently touched surfaces, such as the doorknobs and handles helps too .
  3. Staying warm, eating a balanced diet, and keeping yourself hydrated also help keep  infections at bay.

When to seek medical advice?

You should immediately contact your healthcare provider if you experience any of the following symptoms:

  1. Troubled breathing
  2. Constant chest or abdominal pain
  3. Extreme muscle pain or weakness
  4. Seizures
  5. Troubled urinating
  6. Recurrent fever and coughs
  7. Constant lightheadedness or confusion
  8. Worsening of existing chronic medical condition


Cold weather calls for hot beverages and warm clothes and blankets. It also demands you take preventive measures, such as staying warm, eating healthy food, staying away from people with infections , handwashing and keeping yourself hydrated. These measures may save you from respiratory tract infections in the winter.

Verified By Apollo General Surgeon
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