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.
About Tachycardia (Fast Heartbeat) If you have tachycardia, your heart may beat up to 400 times per minute. This can cause dizziness, lightheadedness, or a fluttering in the chest. Tachycardia is a fast or irregular heart rhythm, usually more than 100 beats per minute and as many as 400 beats per minute. At these elevated rates, the heart is not able to efficiently pump oxygen-rich blood to your body.