I have an elevated heart rate. what are the possible causes if i am healthy?

Anxiety, thyroid?: Chronic stress, hyperthyroidism, poor fitness, obesity, medications can all cause your resting heart rate to be increased. Your physician should be able to investigate further and manage accordingly.

Anemia, hyperthyroid: Assuming you have normal heart function and structurally normal heart, then persistent tachycardia at rest (not related to exercise) can be caused by anemia, fever, and increased thyroid activity.