What's happening in my body when I'm sick?

October 27, 2022 2:27 PM

I'm coming down with something. Out of curiosity, what is causing my symptoms?

Covid test negative and I'm pretty sure that's accurate because I know I caught this from my child, and their test was covid-neg as well. Child had fever, vomiting, malaise, and fatigue.

What causes these specific symptoms?

My palms were itchy last night and today my body, especially my upper back, feels "itchy on the inside". I always get this when I'm sick. Would it make sense for my nerves to get overactive when I'm getting sick? That's what it feels like.
My joints ache, especially my hips and lower back.
I keep having to pee and the pee feels hot when I do.
My tonsils hurt.
My vision feels a bit too bright.
The backs of my eyeballs hurt, as if my eye muscles are too tight.
I have a headache on the outsides sides of my scalp, above the ears.

Maybe I'll feel less woeful if I know what my immune system is doing!

posted by nouvelle-personne to Science & Nature (8 answers total)

Fever?
posted by epanalepsis at 3:14 PM on October 27, 2022

Cytokines!
posted by Tandem Affinity at 4:52 PM on October 27, 2022

Covid test negative and I'm pretty sure that's accurate because I know I caught this from my child, and their test was covid-neg as well.

I am still on the tail end of a Covid infection that I felt the first twinges of on a Friday. I kept testing until Tuesday, at which point I concluded it wasn't Covid (the person from whom I got it had tested for five days after attending an event which was very likely the exposure). Turns out, it was Covid and I just hadn't reached the point where my test was positive yet, even though I was already at the worst of the symptoms.
posted by ssg at 5:36 PM on October 27, 2022

One source of sickness symptoms is your hypothalamus, which listens to your immune system and creates malaise.
posted by Dashy at 5:50 PM on October 27, 2022

My joints ache, especially my hips and lower back.

Aching joints and fever are side effects of interferon, which your immune system produces in response to viral infection.
posted by HiroProtagonist at 6:06 PM on October 27, 2022

If you really want the full scoop, then I heartily recommend the book Immune by Philipp Dettmer. He said fever is thought to be inhospitable to microbes, while making your immune cells more efficient. Inflammation increases blood flow to infected areas, which in turn gives immune cells more access to the virus. I think he also said that there is a theory about why you experience body aches, but I don't remember exactly. Generally, it is thought that when an infection is detected, your body is going to burn a lot of energy fighting it, so it is programmed to send various signals to you to just rest so that there will be enough energy for the immune system activity.
posted by polecat at 6:11 PM on October 27, 2022

It sounds an awful lot like a sub-subclinical version of Kawasaki disease and/or strep infection:

Kawasaki disease (KD) is a systemic vasculitis occurring due to collective immune mechanisms in a genetically susceptible individual, triggered by infections, though the actual cause is yet to be determined. KD is the most common cause of coronary heart disease in children. Typical diagnostic criteria are fever more than 4 days plus four of clinical criteria of cervical lymphadenopathy, skin rashes, mucus membrane redness and lip changes, non-purulent conjunctivitis, peripheral changes in palms and feet In atypical cases three criteria with fever are enough to commence treatment and echocardiograph early. An often-reported association with KD is streptococcal infections. Skin peeling occurs in both conditions, however in streptococcal infections it occurs early while late during convalescence stage in KD except peeling of the genitocrural area that may occurs early. Skin peeling in the streptococcal infection is related to exotoxin while the cause of the peeling in KD is not well known; but it is likely related to the immunological pathogenesis. Another type of skin peeling that occurs recurrently following the initial attack of KD in many months is of an unknown reason. The presentation in this report is exceptional; it is for the first time reporting association of atypical KD presented with post streptococcal complications and vitamin D deficiency followed by the skin re-peeling 6 months after the patients fully resolved. Moreover, it is for the first time reporting nail changes, painful micturition due to urethral involvement and mucus membrane erythema that all resolved without treatment. The cause possibly is related to innate immune mechanism post infections and possible role for vitamin D deficiency paving the way for the post-group A streptococcal (GAS) vasculitis which is an immune response that later acted to trigger the skin peeling.

I emphasized the sections that seem particularly relevant to your experience; your painful eyeballs; your itchy palms and back; and the hot feeling when you pee, respectively.

Strep infections are notorious for developing into knee and hip pains (sometimes referred to as 'growing pains' when they occur in children) and back pain.
posted by jamjam at 6:58 PM on October 27, 2022

The CEO of the Flow Health testing lab got curious about what was causing his sore throat and fatigue and ran a big diagnostic panel. Here's a press release about it. There's a whole corner of his Twitter feed with a bit more on it. (TW for some ableism / sizeism in the way he talks about his lack of comorbidities.)
posted by slidell at 4:23 PM on October 29, 2022