Researchers are reporting that sleep deprivation affects the body's immune system the same way physical stress does.
A small study conducted by researchers measured white blood cell counts in 15 people who were awake for 29 hours. They found that those blood cells increased in number during the sleep deprived phase.
According to researchers this is the same type of response seen during exposure to physical stress.
Lack of sleep has been associated with increased risk of stroke, cancer and weight gain.
There is more on this study in the journal Sleep.