The American Thoracic Society, a physicians' group specializing in heart and lung conditions, on Monday issued new guidelines on the amount of sleep adults need for optimal health.

According to Dr. Sutapa Mukherjee, who chaired the committee that introduced the sleep policy statement, sleep contributes a lot in human health; still no sufficient guidance is there on promoting good sleep health.

On the whole, the group recommends that adults require 7 to 9 hours of sleep a night for optimal health benefits.

Viviane Faria said she usually didn't get proper sleep when she was busy with graduate school. She told CBS News that the amount was 4 hours, 3 hours, 6 hours at most. If one sleeps less than 6 hours in a 24-hour period, it is linked with a variety of health problems and higher mortality rates.

Dr. Kingman Strohl of University Hospitals Case Medical Center told CBS News, "You're subject to certain metabolic problems, such as pre-diabetes; you have more likelihood to have cardiovascular problems and hypertension". Sleep deprivation also leads to drowsy driving and could cause accidents, injuries and deaths.

When it comes to people who suffer from insomnia, the group advised cognitive behavior therapy that helps in dealing with condition, in place of taking sedative sleeping pills. Strohl said that if the pills are discontinued, the insomnia occurs again, however when cognitive behavioral therapy is used, longer lasting sleep satisfaction is there.

It was said that it is always good to get more sleep, but is not always better. The American Thoracic Society's policy statement said that sleeping too much, over 9 or 10 hours a night, could also lead to various health problems.