You must be at least 17 years old to donate to the general blood supply, or 16 years old with parental/guardian consent, if allowed by state law. Learn more about the reasons for a lower age limit.
Other Causes of Elevated Heart Rate. Elevated heart rate when sick is actually your heartâs aid in order to quell the sickness. However, there can be other causes for elevated heart rate as well. Electrical signals produced and sent to the heart tissues are responsible for controlling the heart rate.
This group of specialized cells in the upper right chamber of the heart controls the heart's rhythm by sending electrical signals that tell the heart to beat. In someone with sick sinus syndrome, these signals do not come at a steady pace. Sick sinus syndrome is a relatively uncommon problem.