India, June 25 -- A quick nap is the go-to of many when they find themselves in need of a quick refreshment, especially at home. However, they often wake up from the nap groggy and discombobulated, and occasionally more tired than they were before.

Taking to Instagram on June 25, Dr Kunal Sood, a Maryland-based physician in Anesthesiology and Interventional Pain Medicine, explained why this happens, and what can be done about it.

According to Dr Sood, the reason a person feels more tired immediately after a nap than before is due to a phenomenon known as sleep inertia. Sleep takes place in cycles of light and deep sleep. When one is awoken in the middle of deep sleep, the body finds it difficult to adjust to the sudden shift and therefo...