Definitions of Suspense.

Suspense is a feeling of intense anxiousness, the feeling of waiting for something that seems likely to happen.
Suspense is usually exciting, and can even cause physical changes like an increase in heart rate. Suspense is usually built up by clues which lead to the inevitibitable, something ominous may be shown, but suspense may also be waiting for something good to happen, not only something shocking.
Suspense can not only be shown to the audience by leaving them with unanswered questions waiting to be answered, but also by the audience knowing something a character doesn't.
Suspense can be shown through what a character says, or does, or particularly clues via misc-en-scene are common. This is commonly shown through the setting.A large part of suspense is also shown through music, notably Alfred Hitchcock's use of music was always very famous.

For example, the blood on the floor could indicate that a killer has just killed and the character in that area may be in danger.

I think these settings are particularly scary: which makes a viewer think something scary is bound to happen, this creates suspense.

Suspense can be shown through a 'false Plateu' such as in jaws. We see shark fins and are lead to believe it is Jaws, the killer but then it is revealed that is only children with a fake shark.

But then just after that, the real jaws appears, which doubles the suspense and also makes things 'jumpy'.