
General Aches and Pains
"I feel a bit under the weather."
"I'm not feeling very well."
"I think I'm going down with a cold. I've got a sore throat."
"I've got a slight headache." (Or toothache / stomach ache / backache) Pronounced "ake" as in "cake".
"I'm not sleeping very well at the moment."
"I feel a little faint."
"I've got a nagging pain in my shoulder." (nagging = a pain that won't go away)
"I've got a splitting headache - I hope it's not a migraine."
Sympathetic Responses
"I'm sorry to hear that."
"You don't look very well."
"You look a little pale."
"Maybe you're going down with something. There's a bug going around."
"Maybe you should go home and get some rest."
"Why don't you go home and have a lie-down."
Mild Illness
"I have a bit of a stomach bug."
"I think I've got a bit of a temperature."
"I have a touch of flu." (Flu = influenza)
"I've got a nasty cough." (pronounced "coff")