Here’s Why You Always Feel Sicker at Night


It’s cold and flu season, but no matter what bug you catch you may have noticed you feel worse at night– and it’s not just all in your head.

University of Texas researcher Michael Smolensky says it’s because when you’re fighting something your immune system runs on the same “clock” that regulates your sleep– the circadian clock. Your immune system tends to kick into high gear at night when you’re asleep.

This means infection-fighting cells release all kinda of chemicals, and some of them induce inflammation in the infected tissue. This activity can result in many of your symptoms including having a fever, congestion, or a sore throat.

This also explains why you might feel pretty bad when you first wake up. Science shows your immune system calms down more in the afternoon and early evening, so it’s not weird to feel a bit better around those times and then just feel bad again later on.