Starvation affects the heart rate because blood sugar decreases during starvation and the sympathetic nervous system is excited, which causes an increase in heart rate and blood pressure. At the same time, there will be some other symptoms, such as sweating, weakness, some patients will also appear dizziness and other symptoms, then you must eat sugary food or intravenous push high sugar, etc.. If starvation lasts too long, it may lead to more serious symptoms and even lead to hypoglycemic coma. If hypoglycemia is prolonged, it will cause irreversible brain damage, and patients will have severely impaired brain function even if they regain consciousness after treatment, and serious patients may be unable to take care of themselves afterwards.