Sometime i wake up panicked with fast palpitations & feeling anxious. no sudden loud noise or nightmares trigger it, out of the blue. is this sinister?

?: Assuming that medical conditions such as over-active thyroid and over-production of norepinephrine have been ruled out, this sounds like panic reactions but I do not see any medication prescribed for you to control this problem.

More info: Do the palpitations awaken you or do you awaken with a startle which causes the heart to race? How fast is your pulse when you note the palpitations? How long do they last? Do you also get palpitations on other occasions. A pulse rate of 120 to 150 has more significance than one of 90, for example. A startle reaction may last a minute or 2 as opposed to significant tachycardia. Consult your md.

Sinister? No!: Waking up panicky and anxious with no known trigger is not sinister. This is likely related to anxiety... Consulting with a psychologist or psychiatrist would be recommended to further explore this concern and find ways to alleviate this matter.