08/30/2026
She would come awake at almost exactly the same time every night, around three, with her heart hammering and no idea why. No nightmare she could remember, nothing wrong in the room, just a jolt of panic and then an hour of lying there unable to get back to sleep.
For a long time she was certain it was anxiety, and understandably so, because that is exactly what it feels like. But there is another explanation that often gets missed. When breathing is interrupted during sleep, oxygen drops, and the body responds by releasing a surge of stress hormones to jolt you awake and restart the breathing. You do not feel the pause, because you are asleep for it. What you feel is the aftermath, the racing heart, the sudden alertness, the adrenaline. The pounding heart is the alarm going off, not the original problem.
There is even a reason it tends to happen in those early morning hours. Sleep gets deeper later in the night, which relaxes the muscles around the airway more, so for some people the interruptions cluster in the small hours. That is why it can feel like clockwork.
None of this means anxiety is not real, and it is not a reason to stop any care you are getting. It means that if you are waking at 3am with a pounding heart night after night, your breathing overnight is worth ruling out too, rather than just riding it out. This is testable from your own bed, over multiple nights, with results reviewed by a sleep physician. No clinic stay. No referral needed to start the process. Typically covered by insurance.
DM us TIRED for the home sleep test details and find out what is really waking you.
sleepdisorder.center
Serving patients across Ventura County, Santa Barbara, Los Angeles, Kern, and San Luis Obispo County.
Do you wake around the same time every night with your heart racing?