The condition was officially recognized in 1994 in the DSM-IV (Diagnostic and Statistical Manual, 4th edition) as a specific phobia of blood/injection/injury type. Phobic level responses to injections cause sufferers to avoid inoculations, blood tests, and in the more severe cases, all medical care.

It is estimated that at least 10% of American adults have a fear of needles, and it is likely that the actual number is larger, as the most severe cases are never documented due to the tendency of the sufferer to avoid all medical treatment.

Fear of needles, especially in its more severe forms, is often comorbid with other phobias and psychological ailments; for example, iatrophobia, or an irrational fear of doctors, is often seen in needle phobic patients.

A needle phobic patient does not need to physically be in a doctor's office to experience panic attacks or anxiety brought on by needle phobia. There are many triggers in the outside world that can bring on an attack through association. Some of these are blood, injuries, the sight of the needle physically or on a screen, paper pins, examination rooms, hospitals, white lab coats, hospital gowns, doctors, dentists, nurses, the antiseptic smell associated with offices and hospitals, the sight of a person who physically resembles the patient's regular health care provider, or even reading about the fear.