Understanding what is and isn’t contagious is vital in maintaining our health and well-being. We often make assumptions based on myths, hearsay, or partial information, leading to misconceptions about various conditions and how they’re transmitted. This article dissects and debunks some common beliefs about things you think are contagious but, surprisingly, aren’t. With accurate information, we can better navigate our world, make informed decisions, and perhaps even alleviate unnecessary fears.
Colds Only Through Air
Have you ever heard someone blame the cold weather for their sniffling and sneezing? It’s a common belief that exposure to cold weather or going outside with wet hair can result in catching a cold. However, this is not the case. Colds are caused by viruses, primarily rhinoviruses, which we catch from other infected individuals—not the temperature of our environment.
The misconception likely arises from the fact that we tend to catch more colds during the winter season. This correlation, however, is due to people spending more time indoors in close proximity, thus increasing the likelihood of the virus spreading. Furthermore, the lower humidity in winter can dry out our nasal passages, making them more susceptible to viral infection. So, the next time you forget your hat on a chilly day, don’t fret about catching a cold!
Poison Ivy/Oak
Poison ivy and poison oak are infamous for the itchy, blistering rash they cause upon contact. Many people believe this rash can spread from person to person or even from blisters to other parts of the body. In reality, this is not true. The cause of the rash is an oil called urushiol, found in the leaves, stems, and roots of these plants.
When this oil comes into contact with the skin, it triggers an allergic reaction in susceptible individuals, leading to a rash. However, once the oil is washed off, the rash itself is not contagious. It might appear to spread over a few days, but that’s due to the skin reacting at different rates or the oil lingering on clothes, pets, or gardening tools—not because the rash is “spreading”. It’s important to wash all clothes and items that might have been in contact with the plant to prevent re-exposure.
Warts
Warts, those small, rough-textured growths that can appear anywhere on the skin, are often believed to be easily spread by casual contact. While it is true that the human papillomavirus (HPV) causes warts, simply touching a wart on someone else does not guarantee you will get one. The HPV strains that cause skin warts are usually transmitted through breaks in the skin, and even then, not everyone exposed to them will develop warts.
That said, indirect transmission is possible. Shared environments such as communal showers or pool decks can facilitate transmission, especially if you have cuts or abrasions. So, while you might want to avoid touching someone else’s wart, it’s not nearly as contagious as you might think. Maintaining good hygiene practices is usually enough to prevent the spread of warts.
Grey Hair
Have you ever plucked a grey hair, fearing that more will sprout in its place, as the myth suggests? Contrary to this widespread belief, grey hair is not contagious, nor does it multiply if you pluck one. The color of our hair is determined by pigments produced by cells in the hair follicles known as melanocytes. As we age, these cells may gradually stop producing pigment, leading to the hair turning grey or white.
Plucking one grey hair will not cause more to appear. When a hair is plucked, it will regrow from the same follicle—if that follicle has stopped producing pigment, the new hair will be grey as well. However, the hair follicles around it remain unaffected. So next time you spot a silver strand, don’t worry about it triggering an avalanche of grey.
Cavities
Cavities are another common health issue surrounded by misconceptions. While it’s true that bacteria involved in the formation of cavities can be transferred from one person to another through saliva, it’s not the bacteria alone that cause cavities. Poor dental hygiene, dietary habits, and genetic predisposition play significant roles in whether or not a person develops cavities.
Cavity-causing bacteria, namely Streptococcus mutans, can thrive when we frequently consume foods high in sugar and starch and fail to clean our teeth properly. If these conditions aren’t met, you may not develop a cavity even if the bacteria are present in your mouth. Thus, instead of avoiding your loved ones’ kisses, maintaining good oral hygiene and a balanced diet can prevent cavities more effectively.
