How dangerous is an internal hordeolum to you?

Not too dangerous: Caused by infection of small glands in eyelid but occuring on the inside of the eyelid r/t outside surface. Often requires antibiotic and excision if internal location. Should not be ignored and you should see an opthalmologist for evaluation and management.

Not dangerous: Internal hordeolum is a clogged oil gland of the eyelid margin. It is not an infection. It will usually drain or go away on its own. Worst case it may become a cellulitis (very uncommon, but needs treated) or skin infection, or a nodule in the eyelid that will have to be removed surgically.