He hadn't eaten in a week, afraid of making his mother sicker by drinking her blood.
If he was in bed under the current circumstances, he must be sicker than he was letting on.
If she is whiney and listless, she may be sicker than her temperature indicates.
Science Daily published a report on the fact that the more a person is stressed, the sicker they become.
She objected to the inhumanity of the experiment, since it was clear that the raw fooders were getting better, while the group taking hospital foods and drugs got sicker!
Sicker patients may need to be given the medication through a needle in the vein (intravenously).
The kitten, "Spider," became even sicker and vomited one time.
Thus, if the child seems to be getting sicker instead of better, parents should call the doctor immediately.