The body's immune system responds the same way to sleep deprivation like it does when the body undergoes physical stress, a new study says.

To understand the effects of loss of sleep and body's reaction, researchers compared the white blood cells of people when they had a normal 8 hour sleep schedule to white blood cells taken when they were sleep deprived.

Researchers found that white blood cells in the blood increased in number during sleep deprived phase.

For the study, researchers recruited 15 participants. They were asked to sleep for 8 hours during night. To get their body clocks working in perfect conditions, participants were asked to spend 15 minutes outdoors within 90 minutes during the day. They were also asked to stay off alcohol, caffeine and medications.

During the next phase of the study, the participants were kept awake for 29 hours at a stretch. Blood samples were taken after each phase.

"The granulocytes reacted immediately to the physical stress of sleep loss and directly mirrored the body's stress response," said Katrin Ackermann, lead author of the study and a postdoctoral researcher at the Eramus MC University Medical Center Rotterdam in the Netherlands.

"Future research will reveal the molecular mechanisms behind this immediate stress response and elucidate its role in the development of diseases associated with chronic sleep loss. If confirmed with more data, this will have implications for clinical practice and for professions associated with long-term sleep loss, such as rotating shift work," Ackermann added.

The U.S. Centers for Disease Control and Prevention earlier reported that nearly a third of Americans are sleep deprived.

The lack of sleep has been associated with increased risk of stroke, cancer and weight gain.