Most of us know what the next day feels like after a night of poor sleep. The lingering fatigue. The urge to shut our eyes, if only for a few moments. But there are other reasons you may feel overwhelmingly sleepy during the day that aren’t directly due to sleep deprivation. Surprisingly, one of them is stress.

Have you ever come out of a tense meeting at work or had a difficult conversation with a customer, and soon after felt completely exhausted? That’s the effects of stress.

Sounds counterintuitive, right? You’d think that feeling stressed and anxious would leave you jittery, wired, and a little hyped up. Initially, it might. But the physiological and emotional effects of stress also can leave you drained, exhausted—and ready to curl up on the nearest couch for a nap.

Stress is the body’s response to a perceived threat. “We experience symptoms of anxiety when we feel under pressure, overwhelmed, in danger,” says Jenna Gress Smith, Ph.D., a clinical health psychologist specializing in sleep medicine.

To defend against the threat, your brain kicks into fight-or-flight mode, flooding your body with hormones, including adrenaline and cortisol. This response can trigger an array of physical symptoms, such as a quickened heart rate, dizziness, and even a dry mouth.

“After the stressor or stressful situation is gone, your body will drop into exhaustion mode. Your hormone levels plummet from their peak—and you crash. You could fall asleep standing up. It’s not surprising that you feel drained, even exhausted, as your body recuperates,” Gress Smith says.

If you’re anxious and stressed for a long stretch, your body will stay flooded with hormones outside of its regular, natural rhythm, and the exhaustion can persist, Gress Smith says. In this case, you should consider reaching out for assistance with managing your stress, whether from your doctor or through an Employee Assistance Program.

But there also are ways to help your body cope and recover in the moment to lessen the impact of stress, notes Gress Smith. Physical movement, such as a short walk, will help reduce the levels of stress hormones in your body, while stimulating the production of natural mood boosters. An added benefit: Exercise also has been shown to improve sleep quality to help you get the rest you need.

Deep breathing or a simple meditation also can calm your nervous system, as can listening to some soothing music. Or reach out to a friend to connect. They can potentially provide a different perspective about what’s been going on and offer a sympathetic ear, both of which can help you gain calm.