Iatrophobia- Fear of going to the doctor or of doctors.

Ichthyophobia- Fear of fish.

Ideophobia- Fear of ideas.

Illyngophobia- Fear of vertigo or feeling dizzy when looking down.

Iophobia- Fear of poison.

Insectophobia - Fear of insects.

Isolophobia- Fear of solitude, being alone.

Isopterophobia- Fear of termites, insects that eat wood.

Ithyphallophobia- Fear of seeing, thinking about or having an erect penis.