Chronic insomnia is persistent trouble falling or staying asleep that causes problems for your well-being or functioning.

Everyone has a few rough nights—that's life, not a disorder. Insomnia disorder is diagnosed when trouble falling or staying asleep happens on about half the nights or more, persists for longer than a month, causes daytime problems with mood, energy, or functioning, and isn't better explained by another condition or obvious external cause. Notably, there are no specific cutoffs—"less than X hours of sleep" or "taking longer than Y minutes to fall asleep." Insomnia is in the eye of the beholder.

Through the three Ps: predisposing factors, precipitating factors, and perpetuating factors.

Predisposing factors are what you were born with or developed early—maybe you're just a light sleeper or never had a good sleep environment growing up. Think of these as stacked kindling.

Precipitating factors are the spark: a new job, a divorce, a new baby, a big move, a stressful caretaking situation. For most people, the stressor passes and sleep goes back to normal. But for some, perpetuating factors (the most important P) keep the fire going — and these are often the reasonable-seeming things we do to try to fix our sleep, like going to bed early after a rough night, tracking sleep obsessively, or napping/resting a lot.

Takeaway: You can't change the first two Ps, but you can absolutely change the third. Insomnia runs out of fuel when you stop throwing logs on the fire. That's what effective treatment with cognitive behavioral therapy for insomnia (CBT-I) does.

Because exhausted and sleepy aren't the same thing—and if you’re tired but wired, you probably don't have enough sleep drive saved up yet.

Think of sleep drive as hunger. The longer you've gone without food, the hungrier you get; the longer you've been awake and active, the more sleep drive you accumulate. Most adults need about 16 to 18 hours of being awake and out of bed to save up enough sleep drive for a good night's sleep. Going to bed early, lingering in bed in the morning, napping, or spending a “recovery day” on the couch all sabotage that piggy bank. The result: you're tired, but you're not sleepy.

Takeaway: Learn the difference. Tired feels like worn-out-body asking for rest or a change of pace — a walk, tea, conversation. Sleepy feels like drooping eyelids and a nodding head. Go to bed when you're sleepy, not when you’re just tired.

Everybody wakes up multiple times at night, and 2 or 3 AM is a common time. And most of these awakenings are very brief and you won’t even remember them. When it’s a long and frustrating awakening, it's usually due to conditioned arousal: your brain has learned that being in bed equals being awake and wired.

Here’s how: If your bed has hosted hundreds of nights of tossing, ruminating, and clock-watching, your brain now associates the bed itself with alertness (the same way Pavlov's dog started drooling at the bell). So when you briefly surface during the night (which everyone does), your brain snaps right into "oh, it's awake-and-worrying time".

Takeaway: Two moves help most. First, stop using your bed for anything other than sleep—no TV, scrolling, working, or fretting in bed (sex is fine). Second, when you wake and can't fall back asleep, get up and do something low-key in another room (or at least sit up and read something) until you feel genuinely sleepy again. Don’t try really hard to fall asleep.

The scary headlines you've seen are mostly about sleep deprivation—which is not the same thing as insomnia.

This distinction matters enormously. Sleep deprivation is when something external stops you from sleeping (e.g., a crying baby, only having 5 hours in bed). Insomnia is when, despite having plenty of opportunity in bed, you have trouble falling/staying asleep. Most people with insomnia are actually, on average, getting enough sleep… it just feels like a struggle because the sleep pattern isn’t easy or predictable.

The studies reported as "insomnia causes dementia" or "insomnia will kill you" are typically about sleep-deprived rats or short-duration sleep deprivation in humans. When researchers look specifically at people with well-defined insomnia, the links weaken substantially, and often disappear entirely in higher-quality studies that control for depression, medication use, and other health factors.

Takeaway: Take your sleep (and insomnia, if you have it) seriously, but don't let catastrophic health anxiety layer more stress onto your nights. That worry itself is a perpetuating factor. Know that insomnia is not the same as sleep deprivation.