Why Do I Feel More Anxious at Night?

“At a basic level,” Dr. Pelayo said, “feeling in danger or under stress are the same to the brain.”

Worse, sleep loss has been shown to beget more anxious thoughts. In a 2019 review of 13 studies published in the journal Sleep Medicine Reviews, researchers concluded that insomnia was a significant predictor of anxiety, among other mental health conditions. The researchers explained that sleep helps us distinguish between what’s threatening and what’s safe, so without adequate shut-eye, we aren’t as good at responding to stress, fear and anxiety. This could, in turn, mean more negative thoughts that can interfere with sleep.

The good news is that solid sleep can also make your anxiety better over time, experts say.

How to slow anxious thoughts at night

Since better sleep helps decrease anxiety, general good sleep hygiene practices — like going to bed and waking up at the same times every day and avoiding screens before bedtime — can help on both fronts, Dr. Alfano said.

The tips below, however, might help you reduce anxious bedtime thinking.

Establish a caffeine cut-off. Caffeine’s half-life is approximately five hours, meaning if you have an eight-ounce cup of coffee at 4 p.m., you’ll still have half that cup’s caffeine in your system by 9 p.m. That’s a problem because caffeine not only keeps you awake, it’s also known for making anxiety symptoms worse, Dr. Chellappa said. Instead, consider sipping your last cup of coffee at least 10 hours before your bedtime.

Put your worries onto paper. If you’re prone to overthinking at night, both Dr. Alfano and Dr. Pelayo recommended writing in a journal at the end of the day.

If your ballooning to-do list is making you stressed, Dr. Pelayo said, try writing down all of your competing thoughts and tasks, like: “I need to buy milk.” “I need a new job.” “I never thanked Uncle Joe for a birthday present five years ago.” Doing so can keep the thoughts from creeping up later and, if they do pop up at night, you now have a calming response: Everything important is already captured in the journal.