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.
The hormones made in the thyroid gland affect almost every organ in the body, including the heart. Hypothyroidism can cause the heart to beat more slowly, while hyperthyroidism causes a fast heartbeat. Elevated levels of thyroid hormones also can lead to increases in blood pressure and the sense that your heart is pounding (palpitations).