So there is this belief in our state that if we stand under the rain then we would get ill.As a science student I didn't really understand because for the body to initiate an immune response there has to be an antigen entering our body.While standing in rain, I don't see how the rain alone is going to make a person ill.Please do help solve this confusion and I believe a lot of people would be benifitted from this info.Even a lot of doctors here believe that rain causes fever which made me doubtful too.
2 Answers
This is a common misbelief in many parts of the world. In the English speaking parts we have a similar one about being outside in the cold after which some illnesses are called - you might have heard of the "common cold", which is actually caused by viral infection and nothing to do with the cold at all, though there is an association between the two that I will explain further down.
One way to look at this is - do you bathe or otherwise immerse yourself in water? as in have a shower, or in a bath or swimming pool or river/lake/sea?
If so - does this make you sick or do people think that it makes you sick? So what is the difference between a shower and rain? The answer here is not much - both are water you stand under. One might be warm (heated water in a shower), but could equally be cold with no noticeable difference in perception as to whether it might make you sick.
What does make you sick is acquiring an infection. Infections are typically caused by microorganisms, such as bacteria and viruses (though not exclusively these types, you can also be infected by fungi and things like amoebae and mites), that once inside your body multiply, resulting in the illness.
There are many different types of bacteria and viruses that can make you sick and you have probably heard of at least one - the recent "COVID" pandemic was caused by a virus called SARS-CoV-2, which is a member of the Coronavirus family. Some other members of the coronavirus family cause "common cold" infections, though there are other viruses that also cause similar symptoms and are also grouped as common cold viruses.
You might also have heard of the "flu" or influenza, which is another type of virus. Both COVID and influenza are largely respiratory viruses, which are largely spread by droplets caused by the coughing and sneezing behaviours that are typical with infections of this sort. Talking and similar behaviours (singing etc) also cause droplets, just not as many as a sneeze.
You might also have gone to a doctor with a sore throat and been diagnosed with "strep throat" or streptococcal pharyngitis, which is a bacterial infection of the throat usually caused by Streptococcus pyogenes.
There are also viruses and bacteria that infect other body systems, such as the gut, resulting in diarrhea and/or vomiting, but these are not typically the types that people associate with getting wet by rain or being cold, so I won't go into them.
Now, I said earlier that I was going to talk about an association with being cold/wet and getting sick...
One noticeable thing about rain and cold is that we tend to not enjoy it very much, so we shelter from it rather than stand around getting cold and wet. As an example, you might have seen people huddling in a bus stop or under an awning waiting for the rain to stop. One common feature of these events is that it puts people close together, which means that we are more likely to be able to pass along any illnesses we might have; especially those that are spread by droplets. This was the reason for the 2 metre/6 foot spacing rules that many countries implemented during the recent COVID pandemic. There's also some scientific evidence that cold weather1 and humidity2 play roles in survival of some the respiratory viruses outside the body.
So, long story short: being cold and/or wet doesn't actually cause illness by itself, it just enhances transmission conditions so that you are more likely to get infected by a virus.
Refs:
Lowen AC, Mubareka S, Steel J, Palese P. Influenza virus transmission is dependent on relative humidity and temperature. PLoS Pathog. 2007 Oct 19;3(10):1470-6. doi: 10.1371/journal.ppat.0030151. PMID: 17953482; PMCID: PMC2034399.
Shaman J, Kohn M. Absolute humidity modulates influenza survival, transmission, and seasonality. Proc Natl Acad Sci U S A. 2009 Mar 3;106(9):3243-8. doi: 10.1073/pnas.0806852106. Epub 2009 Feb 9. PMID: 19204283; PMCID: PMC2651255.
TL;DR: no, standing under rain does not lead directly to being sick.
As this article says:
Contrary to popular belief, being out in the rain does not automatically make you sick. While the rain itself does not make you sick, it does play a role in how you could catch an illness
This claim is done by health experts working in emergency rooms, hence credible enough in my opinion.
The article then goes further to explain how rain might indirectly cause sickness, and ways to avoid it.
