Yesterday, in my article about Where Love Once Lived, I told you about ways to add conflict between characters to your novel. I ended the article by saying there are other ways to add tension to keep those pages turning.
In The Complete Handbook of Novel Writing, Carol Davis Luce defines tension as "the act of building or prolonging a crisis." She goes on to give some examples and ends the chapter with this: "How you build that suspense can make the difference between your readers chucking your book for a good night's sleep or nudging their spouse to say, 'the suspense is killing me.'"
In addition to the conflict between characters, there is also inner conflict. In the same book, referenced above, Kathy Jacobson describes ways to give a character an inner conflict.