Committing acts of kindness lowers blood pressure. According to Dr. David R. Hamilton, acts of kindness create emotional warmth, which releases a hormone known as oxytocin. Oxytocin causes the release of a chemical called nitric oxide, which dilates the blood vessels. This reduces blood pressure and, therefore, oxytocin is known as a "cardioprotective" hormone. It protects the heart by lowering blood pressure.