Hi dear... how old is your husband? Does he have diabetes or hypertension?
Is he having proper meals or is he having a
lack of appetite since the cramping?
I would suggest you to give him Tab.
Paracetamol to control his fever and brufen for the pain . Also put him on any
multivitamin of your choice. The vitamins will take care of the cramps.
Then you need to get a few blood tests done, a
complete blood count, thyroid level, sodium, potassium,b6,
creatinine and urea levels. Also get a routine urine test done if he complains of burning urination.
You can either give him oral multivitamins or weekly injections of neurobion. THis should help.If all the reports are within normal limit. Then your husband is probably fine.Flu as you mentioned is aviral infection and will be self limiting, one has to manage it only symptomatically, by rest and painkillers. In case your husband is above 40, do get a basic ECG also done.
I hope this answers your query dear.
You can show your reports to the ER doctor or get back to me with the details.
Take care dear.