CBL4 said:
I am not sure this is a meaningful question or not but are the symptoms a side affect of the cytokines or are they part of the defense?
The only answer to this question, and unfortunately it's somewhat cagey, is simply "yes". The cytokines invoke a physiologic response. These are, for various reasons, necessary in fighting off the infection. So, they are both the causative agent of the symptoms you feel and part of the defense. Make sense? Obviously we have evolved in such a way that this is both a physiologic and functional consequence of their action upon our bodies.
CBL4 said:
I can see that it would useful for me to rest after the flu but I am not sure about the benefit of body aches.
If you have body aches, you don't feel like moving around much. If you don't feel like moving around much, your body's energy resources can be focused on healing. Remember, it requires a lot of energy to fend off an invading virus. If you are using that energy to instead run around and, say, hunt wooly mammoth, you're either much more likely to have a prolonged course of the infection and/or succumb to it. If your body is aching, your much more likely to sit/lay still until the aches go away.
CBL4 said:
As to fever, I read a newspaper report a few years ago that said that fever was useful in fighting off diseases and taking medicine to reduce fever actually reduced the body's ability to fight infection. Do you know if this is correct?
Well, fever is a physiologic response that is a by-product of the hypermetabolic state. Fever response is controlled by IL-1's action in the hypothalamus. But, start with the concept of what exactly causes a fever to occur. Recall that mitochondria are the main energy factories within the cells producing ATP as the main energy store. This process is not 100% efficient, and the by-product of the chemical reactions is heat. In the normally regulated body, this gives us a mean core temperature of 37.0C/98.6F. If the control mechanisms are altered or deregulated by a supervening mechanism (in this case IL-1), then the mitochondria can go into overdrive and, as a result, the body's temperature rises due to the increased reaction within the mitochondria.
Now, whether or not the temperature itself actually helps eliminate virus(es) is still a subject of debate. There is some speculation that an increased core temperature may partially inhibit, or at least diminish the efficiency, of certain intracellular replication mechanisms of specific viral proteins. Remember, viruses invade cells and take over the cellular machinery of the host cell in order to make new viruses. If excess heat intereferes with or slows down this process, this may give the body's defensive mechanisms more time to act. Again, this is mostly speculation.
So, whether or not the fever is actually beneficial in expediting the elimination of the virus remains arguable. It clearly is, though, a by-product of the hypermetabolic state induced as the body "ramps up" to fight the infection.
CBL4 said:
Also, does fever cause the inability to think clearly? Or is it some chemical or is a combination?
Theoretically, you could have a fever so high that your native proteins begin to denature. There is supposedly the "threshold" temperature (roughly 107F) where certain stuctural proteins will start to break-down. However, this is not the case during the normal course of a fever. But, since you are in a hypermetabolic state during fever, it is more likely that everything is a little "wacky" (that's the official scientific term, BTW
) from a physiologic standpoint, and your brain's functioning at a higher than normal level. As the metabolic demand increases, so do the metabolic respiratory by-products. I can only speculate that this a combination of these two things are what causes the "foggy" feeling and the fever dreams that people. I'm not sure that anyone really knows at this point. So, to reiterate, that is speculation.
-TT
(edit: numerous typos... probably more still there)