Nocturnal panic attacks are frightening, like any other panic attack, but can be harder to explain. These attacks could be a result of panic disorders and may share the same physical responses as night terrors, but they are not part of a specific diagnosis in the Diagnostic and Statistical Manual of Mental Disorders.
Panic attacks are similar in both the night and day; most people experience a rapid heart rate, child, shortness of breath, and tremors. When you feel stressed or anxious, your stress hormone production goes into overdrive, and it doesn't stop even when you're asleep, so insomnia and a lack of rest can cause panic attacks.
The best thing to do when you get a panic attack is to normalize the experience; fighting the feeling can make it worse, so stay still and do something relaxing to help yourself wind down. Also, conditions such as thyroid problems can mimic signs of a panic attack, so if you're suspicious of your symptoms, go see a doctor.