Why do we sometimes v* with the flu??

[thecheesecake17]

I came down with what the doc described as 'swine flu' in December 09, although my dad laughed it off and just said it was the common flu....eitherway it had me in bed for a full ten days, and it started off with a bit of D* ...twice in an hour then came the horrific n* that I remember starting at 8pm until I went and dry heaved with a scorching fever from 12-1ish in the morning. After that, though...I woke up to zero n* and the WORST flu ever...pains, aches, chills, headache...death feeling..but no sickness. In fact, I was starving by the next morning....but I'm confused cos my friend who's studying biology laughed when I said 'I'm scared il be sick through flu' and said 'the flu is a different thing to tummy bugs' which I get, but why did I almost throw up if it was, as he described, 'respiratory'??

[crd08]

d* and v* is more common with H1N1, but not so with influenza. Swine flu is a bit different, it infects us deeper into the lungs, and it can cause worse/different symptoms.
Some people do have d* or v* with influenza, it's just not as common and more likely in children. Some peoples's digestive systems are touchy to the mucus running into their gut. For some its the high fever. I've had d* with the flu before as a kid, but never threw up. It's not that it infects your stomach, just the other symptoms in SOME people cause these reactions.
Overall your friend is right.

[Malalcala]

Hmmm.. your friend is right that bacteria and viruses that cause "gastroenteritis" have specific functions that cause nausea, vomiting..etc. That being said..the way your body responds to a really bad illness may cause GI upset, (You totally could have had H1N1 that year!! I don't know if your doc did the test but it's not unreasonable.. "common flu" could be any strain of influenza that is common in the population that season.. I think H1N1 was a thing that year. It is also unique in that it tends to be harsher on the young because their healthy robust immune systems throw down the gauntlet and overrespond a bit.)
Anyway... Sometimes illnesses that are not gut specific have nausea as a side effect. Strep throat for example is totally a "pharyngitis" but nausea and vomiting are common in the initial prodrome of the illness, this is most likely due to the CRTZ (chemo receptive trigger zone) in your brain picking up an influx of chemical signals from pain, the immune response, stress etc..
(someone posted an article here a day or so ago that talked about this effect a bit.. it related specifically to serotonin and the stress response but the mechanism is similar).

That being said... nausea and vomiting aren't by any means "common" in influenza. Being an emet myself I really, really don't want to give any information here that would cause additional anxiety!! Most times we will catch many o upper and lower respiratory bugs without any anxiety inducing side effects!

On a side note... i think the flu shot generally includes H1N1 these days ; )
~M

[jkl81]

I have had severe n* with influenza and some d* at times. I felt close to v* a few times with standard seasonal flu in 1999 and 2000 that I was panicing thinking it would happen, but it did not. I hated that flu so bad that I have gotten my flu shot every year since then. I think v* would be a more unlikely symptom with any of the flu viruses circulating out there whereas a main symptom of some forms of food poisoning and some viral GI infections. For me the flu equals: mild to moderate nausea, no appetite, high and undulating fever, persistent cough and sore throat. It usually takes me about 2-3 weeks to really shake it. After v* causing bus,it is my second least favorite minor/moderate illness. I hope I never get it again! Several here touched on it: the 2009 H1N1 was a pandemic flu virus. Malacala is the medical person in training here, and hopefully will correct me if I'm mistaken, but as I recall, pandemic flu represents major genetic drift in the virus, leading to a version of it that our immune systems sometimes have a hard time with since they haven't seen it before. In a normal year the flu virus (and our enemy the noroviruses, and all RNA viruses) show minor genetic drift and different strains predominate every year. That's why it's hard to create effective vaccines for these guys and why a flu vaccine is usually only good for 6 months to a year.

[thecheesecake17]

Fascinating!! Woah, I've learnt so much, thanks guys. Just read an article which was about how difficult it is to differentiate between the seasonal and swine flu and patients with swine supposedly reported the nasty stomach that I had, but who knows right? As you all mentioned, n* seems to be a side effect even with colds, and its a chemical thing aswell as infection...crazzzyy. I also wondered why all my 22 housemates last year in university were throwing up food with the 'fresher's flu' when each year I've been perfectly able to eat...strange...feel lucky. Shouldnt get too cocky though, I started class again this morning!!

Anyway, thanks for the replies guys, can't wait to educate my family and friends with these facts haha.

[Malalcala]

"pandemic flu represents major genetic drift in the virus, leading to a version of it that our immune systems sometimes have a hard time with since they haven't seen it before. In a normal year the flu virus (and our enemy the noroviruses, and all RNA viruses) show minor genetic drift and different strains predominate every year. That's why it's hard to create effective vaccines for these guys and why a flu vaccine is usually only good for 6 months to a year.[/QUOTE]

Hahaha as far as I know this is pretty much verbatim microbiology/epidemiology.. I think a Pandemic only occurs with influenza A whereas an "endemic" can be in A or B strains... But I am no epidemiologist so it seemed a bit like semantics to me : )
As far as fun facts are concerned...I do know that the 1918 H1N1 "Pandemic" was hugely devastating and that when we were learning all this stuff the prof took a moment to point out that Edward Cullen (from the Twilight books) would have "died" of that strain in Dr. Carlisle hadn't rescue him... Med school is strange.
jkl81 is totally right about the 6 month flu shot efficacy... We use last years strains and try to predict what will be prevalent in the population this year and then hope for the best.

Also... I have no idea how to work quotes.. Sorry!!!