Is there a level of intensity you have to feel for that phobia, or does your fear have to be crippling to be called a phobia?

Like death or spiders, most people are afraid of death and spiders, but is it really called a phobia or is it just a fear?

Or what about people who are afraid of numbers, is it a phobia because most people are not generally afraid of numbers?

What about people who are afraid of sharks, despite that they will likely never put themselves in a situation where they are near sharks, is that a fear or a phobia?

I'm afraid of germs, it's irrational (in my head it's not) but I avoid certain things like touching garbage cans (I haven't taken out the trash in over 7 years) and I wash my hands frequently. Is that a phobia or a fear?