The phobia of needles is known as needle phobia or trypanophobia. It is an extreme fear of medical procedures involving injections or hypodermic needles, which can lead to avoidance of medical care and vaccine hesitancy. Needle phobia can be learned from a past experience of pain, but there is also a biological component that makes some people react very strongly to the idea of procedures involving a needle. The most common type of needle phobia, affecting 50% of those afflicted, is an inherited vasovagal reflex reaction. Approximately 80% of people with a fear of needles report that a relative within the first degree exhibits the same disorder. Symptoms of needle phobia include extreme anxiety, elevated blood pressure, and heart rate at the immediate point of needle penetration or seconds before. The recommended forms of treatment include some form of anesthesia, either topical or general. People with needle phobia may delay or avoid necessary medical care, and it can significantly interfere with their life.