Those who have spent time in the hospital know that it's nearly impossible to get an uninterrupted night's sleep, due to constant visits by the medical staff. Last week, Theresa Brown, RN, a nurse who admits to waking up patients, wrote an article for The New York Times Well blog explaining why this is so common. For starters, she says that nurses needs to check vital signs, administer antibiotics and have the results of lab tests ready for the doctor's early morning rounds. (In this telling anecdote about a cranky insomniac, an unsteady nighttime urinator and a delusional woman, she shows us how quickly the most organized nurse's plans can go awry.)

Most importantly, Brown acknowledged that a good night's rest is crucial in helping patients recover from whatever it is that landed them in the hospital in the first place. But you don't have to be sick or injured to take advantage of the benefits of sleep. Here are three ways that a dose of zzz's can improve our health:

1. It helps us ward off colds. A 2009 study in the journal Archives of Internal Medicine showed that those who sleep less than seven hours a night have a three times higher risk of getting a cold than if those who sleep more than eight hours. That extra hour or two really matters.

2. It allows our systems to reboot. Sleep replenishes your cells and allows your body to carry out important maintenance duties like strengthening your immune system, balancing your hormones and repairing fatigued muscles.

3. Getting the right amount of sleep may extend your life. A 2008 study in the journal Sleep found that, among elderly women, sleeping between five and nine hours was associated with a lower risk of mortality.

If only we could send sleep as a get-well gift...or at least FedEx ill friends a mug of warm milk.