In the next situation...:
(I am talking with my friend in the afternoon about something which happened to me in the morning. As you can notice all happened in the same day...):
Me: I woke up this morning and I noticed an huge pain in my leg, so I think it is hurt (hurt is in Simple Past).
I said: "It is hurt" automatically, but I do not know the reason, I translated fast in my mind and it sounded good for me, but... if I analyse a little the sentence, when I said "I think it is hurt" that problem could has my leg yet, in the moment that I am talking with my friend (a muscle could be damaged or something but I do not feel the pain in that moment). So... Why do not I use: "I think it is hurting"?, for me it has not much sense, but talking gramatically for me it does not seems a bad option because as I said before it is something which I could have in the moment that I am talking (an hurt in my leg).