Nightmares

The strange dreams I dreamt with repetition are only odd dreams. About from last year, I started to have these sorts of dream:

1. I saw myself from the glass door of the bookshelf, so pale, mouthful of fresh blood was dripping out, and my throat was grasped by a pair of invisible hands. I felt suffocated and struggled to wake up from the dream, my heart beat fiercely… the dream was so real, I really breathed hard.

2. I saw myself through glass door. My mouth shed blood. Once opened my mouth, teeth came off one by one, and dropped. I woke up. I was terrified. I toughed my teeth at once and knew they were still there, however left a lingering fear.

3. I was looking into a mirror, as if a dental check. My teeth suddenly turned into fragile white coral, blood oozed. Furthermore, my teeth were numb, my gums and cheek swelled and galled… after woke up my gums were really swelled.

4. A dream in a dream. I struggled to open my eyes, the clock was pointing at 11 a.m., I immediately got up and washed and dressed; suddenly I back to bed again, it was after 2 p.m. already, I got up hastily; and then I struggled to get up again… as if I was awake, and finally I opened my eyes with difficulties, it was only about 8 a.m. How come it was so real?

5. I saw myself woke up from sleep. All on a sudden, two invisible hands were pressing strongly my belly and waist and back, so ache. My hands struggled to get free but failed. I was pressed vigorously twice more… I do not know if I had once gotten back conscious, all in all, the feeling was so real. When I woke up in the morning, my belly and waist and back were all in aches.
Could it be said that I was pressed by those odd hands?

Does anyone who can interpret dreams, can tell me why I had the dreams with such a sense of reality? I am puzzled.