I have asthma and often wake up in the night literally having trouble breathing. The little bit of water trick Chalmette uses works for me/that as well.

I have a little ritual I follow when I wake, I go down to my dresser where my inhaler is and take a puff (or two), go to the bathroom, come back to the dresser and take a sip of water and then go back to bed. Sometimes I check to see if I'm hungry or my stomach feels "odd" and I'll have a Pepcid Complete in case there's acid reflux or something complicating my asthma. If I'm truly hungry I might go downstairs and have a small carton of yogurt or bagel or toast and come online while I eat for a few minutes then go back up to bed.

But having a little ritual helps me, makes me feel "safe" and comforted. I feel like I'm more in control. I put it into action for whatever reason I wake, whether it's a bad dream or breathing problems or just having to go to the bathroom or being too hot/cold/physically uncomfortable.