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.
Cells in your heart make electric signals that cause your ticker to pump at a regular pace. If you have AFib, your heart's two small upper chambers (the atria) don't beat normally. Instead they beat too fast, with the electric signals triggered from different parts of the chambers. That causes a rapid thumping in your chest. You may also have dizziness, sweating, chest pain, or shortness of breath.