Woke up from à nightmare with HR of 80.Why is this if your are sleeping? Isn't your heart supposed to be resting at a lower rate not reacting to fear?

Panic Disorder. I understand your distress. Nightmares can have panic, sweating, increased heart rate and respiration due to painful traumatic experiences with unresolved conflicts. Your State has Wonders of Everglades National Park. Visit, feel Peace; release feelings of anxiety, fear, panic, hurt, resentment, guilt. See a Psychiatrist for diagnosis of Anxiety or Panic Disorder, have Medication and Therapy.