Intimacy may be tougher. While separated, it's hard to create intimacy. It's hard to stay connected in a long-distance relationship.
Miss each other. Though apparent, this is worth addressing. Missing each other makes couples unhappy and lonely.
Communicating may be difficult. Long-distance relationships demand more communication. To remain in sync with your spouse, you must be more aware.
You may feel distant. Staying in touch while you're apart might be difficult. You may feel less connected to one other and miss out on basic day-to-day experiences that couples in close proximity get to enjoy.
Conflict resolution may be difficult. Conflict resolution is harder when couples live apart. You may linger on tiny concerns and can't hug to make things better.