Hi @annie1995 and welcome to the forums! Good question. I’ve personally found that my heart rate spikes correspond to the times I get up to use the restroom. Also, and I’m older than you so it may not apply, but I’ve noticed that my nighttime heart rate is normally higher than my resting HR when my arthritis is acting up and my sleep is more restless. A google search suggests other possible reasons but ask yourself ... are you consuming caffeine or alcohol too close to bedtime? Have you tried using the Fitbit Relax app before bedtime? That could help.
Of course the best answers will come from your Doctor. If you are concerned, track your HR differences and bring them to your next appointment.
I’m moving your question to the Sleep Well forum where you may get more suggestions/answers.
