Let’s say I have a cold, and I’m coughing and sneezing and have a runny nose.
Is the virus. . .
A) In my body as a whole, like in my blood stream, and it somehow is sending signals to make me sneeze and cough?
or
B) Just in my nose and throat, and my symptoms are my body reacting to the irriation of the actual virus in residence in my nose and throat?
In general, are viruses typically localized? For instance, a flu virus that has me puking and trotting. . .is that a “general virus” that causes those symptoms, or is it really a virus that is just in my gut and my reaction to that virus to puke and trot?
Here’s a bump for your thread, so someone more knowledgeable can pop in with more specific info.
All of the viruses I can think of offhand prefer specific areas of the body. Your symptoms are part of your body’s attempt to get rid of the virus, for example, sneezing can help clear the virus from your system. If you’re puking and trotting, the virus is most likely “living*” in your gut.
*quotes, since they’re not technically alive. They need the host’s cells in order to replicate
For the life of me I can’t understand why no one else has answered this yet. I’m going to reiterate that I am not an expert, but I can take a stab at this until someone who knows more about it can clarify.
Many people agree that viruses are no organisms, so it might make it easy to think of them as pieces of protein that are able to invade some specific type of living cells and hijack them into factorys that reproduce the virus. But the mode of attack is very specific to different types of cells. That’s why a “cold” has similar symptoms to the same “cold” that someone else had. That specific virus has been designed (designed is a terrible word for this but I can’t think of a better one) to only attack a certain type of respiratory cell, and therefore a cold doesn’t result in a sore foot, because the virus is only in those cells related to your respiratory system.
one of the better ways I have to describe this relates to hepatitis. You are probably familar with how humans are afflicted with Hepatitis A, Hepititis B, and Hepititis C (there is also D + E but usually only relagated to rare third world appearances). All three of those I mentioned affect the liver specifically, all in different ways. Hep A is a short term type of food poisoning, while Hep B and C are incurable long term degenrative diseases. One being sexually transmitted the other being a blood borne pathogen transmitted through such means as uncleaned needles. Hep B has a vaccine, while Hep C does not yet. Now even though all three affect the liver, when you look at these three viruses in particular you see that there is no relation at all. The only reason they all have the same name is that they all affect the liver and the liver alone.
So that’s why when you have a cold you have cold symptoms, and when you have hepatitis you have illness of the liver. The virus is designed to only infect a specific type of cell.
No need to correct - you hit it on the head. Different viruses infect different types of cell, and will therefore cause different symptoms. Cold viruses settle in the respiratory passages and cause your sniffling and sneezing. Other viruses prefer the liver, the nervous system, the gastrointestinal system, and so on. The symptoms you feel are a combination of viruses’ effect on those types of cells (disrupting their function or killing them outright) and your body’s reaction to the infection.