Why do people get insomnia? Doctors explain what happens in the brain when we can't sleep

It is an indisputable fact that our bodies need sleep — so why does it struggle at times?

Insomnia is when you have difficulty in initiating or maintaining sleep, even when you want to rest. It can be short-term (less than three months) or chronic (more than three months).

Why does it happen?

According to St. Luke's expert in Adult Neurology and Sleep Medicine, Dr. Nikki Perez, certain predispositions make people more susceptible to developing insomnia.

"Advancing age, female gender, and low socioeconomic status are the strongest risk factors for insomnia," she told GMA News Online.

A stressful event can also trigger short-term insomnia, while chronic insomnia may be caused by major life changes or other co-occurring psychiatric conditions, she added.

What happens during insomnia

In insomnia, the body remains in hyperarousal — the state of "fight or flight" — even at bedtime.

In other words, Dr. Perez said, the "switch" that normally turns off so that sleep could occur "breaks down."

Furthermore, the stress switch also stays on.

"Cortisol should be at its lowest in the evening, but in people with chronic insomnia, it stays elevated into the night. This keeps the norepinephrine system active — the same neurochemistry behind the fight-or-flight response," she said.

There's also such a thing as the circadian rhythm, generally known as the internal body clock. Normally, it releases a "time to sleep" signal, but in insomnia, this signal is often blunted or delayed, "so there's no strong biological push at the right time."

All this can get further aggravated by bad sleep hygiene.

What makes insomnia worse?

Psychiatrist-sleep specialist Dr. Rose Anne C. Roque told GMA News Online that certain habits or behaviors can worsen insomnia, such as irregular sleep times, exercising late at night, drinking alcohol, and using electronic gadgets before bed.

She also stressed that trying too hard to sleep might be counterproductive.

"Clock watching may increase sleep anxiety and frustration," she said. "Obsessing on sleep would be counterproductive because the more you focus on controlling it, the more you can’t."

Dr. Roque said that those with insomnia cannot simply "lie down and close their eyes."

"With insomnia, the more you try, the more you can’t. Forcing yourself to sleep only increases the pressure, the stress and the frustration which may actually cause the hyperarousal. It is like commanding your brain to do something hence, making it more alert," she said.

When to see a doctor

Chronic insomnia is associated with a higher risk of adverse health outcomes and may ultimately contribute to increased mortality risk, Dr. Roque said. Thus, it is important to get it treated.

"For insomnia due to poor sleep hygiene, irregular schedule, being mindful of sleep compatible practices may help," she said.

"For insomnia due to other causes like stress, anxiety, mood concerns, the cause should be addressed."

Dr. Perez recommends seeing a sleep specialist as soon as signs of an insomnia disorder develop.

"There is no one-size fits all treatment for insomnia, and seeking advice as early as possible aims to identify the cause and break the vicious cycle," she said. —CDC/GMA News