Abigail Fowler started suffering from insomnia – which is Latin for "no sleep" — after her sleep cycle was interrupted during the years she breastfed her children.

"My body and mind adjusted to needing to wake at a moment’s notice," says Fowler.

Fowler’s insomnia creeps up about two nights a week and often for seemingly no particular reason.

"It's perpetual, any night is suspect. It doesn't consult me, just shows up," she says.

According to the National Center for Sleep Disorders Research at the National Institutes of Health, about 35 percent of adults say they have some symptoms of insomnia and about 10-15 percent report chronic insomnia.

It’s difficult to define insomnia because it’s different for everyone. People need different amounts of sleep to feel rested, so insomnia is better defined as the quality of sleep and how one feels after sleeping as opposed to how many hours of sleep one gets.

"I might be in bed for eight or nine hours, but I will actually only be sleeping for three hours or I might be lightly sleeping, not deep sleeping, which makes me just as tired the next day as not sleeping," says Aaron Jackson (not his real last name).

Insomnia is usually a symptom of another problem, which also differs from person to person. 

The causes of insomnia include stress, depression, anxiety, trauma, fear, grief, diet, lack of comfortable / dark enough environment or medical problems such as reflux, asthma or allergies. 

For Jackson, insomnia is usually a symptom of stress.

Jackson says he started getting insomnia when he was in college and was stressed about papers or exams. After graduation, he had different stresses with work and eventually family, and now, any time he doesn’t take a sleep aid or have a couple of cocktails, he finds himself unable to fall asleep.

What to do when insomnia strikes also varies form person to person. 

"I’ve tried counting sheep or drinking warm milk but often I just get up and watch TV," says Jackson.

Fowler says if she can’t sleep before 3 a.m., she just stays in bed, but if it’s after 3 a.m., she usually gets up. 

Occasionally, Fowler uses melatonin or Sominex to help herself fall or stay asleep. Writing helps, too.

"I have a pen and pad of paper next to my bed. I often can't stop thinking about the things I need to get done in the coming day or days. If I write it down my mind can let it go," she says.

Although insomnia is often a psychological game, it sometimes can be alleviated or minimized through physical practices such as avoiding naps and establishing a regular routine and sleep cycle. Lack of sunlight during the day can also cause insomnia. For some people, insomnia occurs more during the winter months than in summer.

"This is true for me," says Jackson. "But I chalked it up to general winter malaise rather than a sunlight deficiency."

It’s also recommended that insomnia sufferers stop drinking caffeinated beverages at least eight hours before bed and avoid drinking alcohol at night because it makes people "pass out" which is not a form of quality sleep. And because nicotine is a stimulant, smoking at night is not recommended, either.

However, despite the annoying and discombobulating aspects of insomnia, there are sometimes valuable lessons learned through it.

Jackson, who writes science fiction short stories as a hobby, says he has written some of his best work when he couldn’t sleep.

And Fowler says she is no longer fooled by how daunting things seem in the dark.

"I've realized that the thing you are awake with in the middle of the night doesn't feel as heavy or scary the next day in the light," says Fowler.