If you're not getting enough sleep these days, welcome to the club.

People who don't get enough sleep may feel fatigue during work hours or fall asleep during inactive times, such as while watching tv or reading. (studiovespa, ThinkStock)

Recent data shows 28 percent of New Jerseyans sleep fewer than than six hours an night, and a new study finds on-the-job performance quickly deteriorates when workers sleep less than six hours.

According to Dr. Mangala Nadkarni of the Medical Director of the Sleep Center at St. Barnabas Medical Center in Livingston, most people need seven to eight hours of sleep a night.

"If you don't get enough sleep it can cause all sorts of problems that people may or may not be aware of," she said. "They can doze off when they're inactive such as when they're reading or watching TV, or unfortunately even when they're driving on the highway. They may fall asleep at the wheel, or sometimes people may fall asleep even when they're stopped at the traffic light and that can cause an accident."

She said the national sleep deficit causes roughly $60 billion a year in lost productivity, "because people are not able to concentrate on the job."

"If we want to be able to fall asleep we have to give ourselves time to wind down," she said. "Especially in teenagers, we tell them make sure that they're not on the cell phone, they're not on the computer. People are quote, unquote 'wired' all the time for no reason and that makes it harder to sleep."

The chemical melatonin helps us to fall asleep, but if you're exposed to light at night, she said, "it inhibits melatonin production and makes it harder to get to sleep."

Dr. Nadkarni said the most common sleep disorder - that more than a million Jersey residents suffer with - is insomnia. Also, there is sleep apnea, a chronic condition that disrupts sleep and can lead to serious health issues, and also a condition dream enactment, "when people start acting out their dreams, they're screaming, yelling during the night."

She pointed out many people tend to get sleepy around the so called "siesta time" of 2 to 3 p.m. in the afternoon, the most common time to take a nap.