We all know the routine by now. Around mid-to-late fall, advertisements and public service announcements start to urge everyone to get their flu shots. By time the holidays have passed, it seems impossible to make it through the gatherings without catching the flu—or at least knowing friends or family who came down with it and had to cancel their plans. Why does the flu always seem to appear as things cool off for the winter months? While it’s possible to come down with the flu at any time of the year, cases always seem to ramp up and wind down in a seasonal pattern. Below are a few factors that can add up to explain this trend.
1. More time indoors makes it easier for the flu virus to spread
While germs like the flu are always present, the winter weather makes it easier for us to spread them among each other. This is because we spend more time indoors, making it easier for personal items like bedding and towels to get contaminated. More people will also be inside at the same time, close to one another, making it easier to catch the flu by breathing in droplets of moisture left behind.
2. There is more travel in the winter
With the travel season being stronger in the colder months, it’s easy for people to pick up a virus and carry it from place to place, allowing it to spread from country to country. This makes it even easier for the flu virus and other illnesses to spread through droplets of moisture left behind after an infected person sneezes or coughs.
3. There is less ventilation
People spend more time indoors during winter because they don’t want to risk getting cold or catching a chill. This means that they stay in closer contact with one another, and this creates a greater risk of spreading illness. Architects often install ventilation systems to deal with this issue, but they may be used ineffectively or not maintained well enough to prevent the virus from spreading.
4. There is less sunlight
Because of the darkness, people will spend less time outside during winter. This reduces exposure to sunlight, leading to an increased risk of vitamin D deficiencies which can make it easier for illnesses to spread. Ultraviolet light from the sun is one of the best ways to promote healthy levels of vitamin D and reduce the risk of flu and other illnesses during winter.
5. The immune system is weaker in winter
Another reason there is a flu season in the winter could be due to how the weather affects our ability to fight off illness. In summer, the body’s immune system functions at its peak, with white blood cells fighting off illness and keeping us healthy and happy. In winter, the immune system is often weakened due in part to the lack of vitamin D mentioned above. Even when flu season begins, a weaker immune system means that the body’s natural defenses against illness might be less likely win a battle against the flu.
Key Takeaway
The flu is a serious health threat that can have severe consequences, especially for the weak or elderly. While there is a flu season in the winter, understanding what caused it can help us prevent illness and get you through the cold months without being overcome by sickness.
