Even the sound of a dentist's drill can be intimated for people who are scared of dentists.

Yet dentist Jochen H. Schmidt's advice to anyone reluctant to come for a checkup or longer procedure: come in the afternoon, because at this time of day patients feel less pain caused by injections and drilling.

This is due to pain-inhibiting endorphins and opioids, which the brain produces in particularly large quantities at this time of day, according to the dentist based in Cologne, Germany. An anesthetic will then work a little better and, above all, last a little longer.

According to some estimates, about 12% of the population have a fear of doctors, while with children it's as much as 19%, although patients with severe iatrophobia are thought to be fewer.

People who are afraid of doctors, in general, suffer from what's known as iatrophobia.

Experts say the problem is often that the longer that iatrophobics put off seeing a doctor, the worse their condition becomes. Hence the medical procedure ends up being more unpleasant if they finally do see a doctor, which only validates and intensifies their fear – a vicious cycle.

Fortunately, iatrophobia can generally be cured with cognitive behavioral therapy. The patient and therapist analyze the sequence of events in a doctor's surgery as if in slow motion. Afterward, the patient is gradually exposed to the triggers of his or her fears.

Dentists in particular now offer to treat fearful patients under general anesthesia or hypnosis. Relaxation techniques or distractions such as music or movies can also be helpful. And it's important that patients facing surgery not suppress their fear.