Lack of water:
I drink a lot of water over the course of a day. If for whatever reason I don't drink any I get all headachy and then I get cranky.
Lack of food:
I eat at least 3x a day. If I skip a meal or it's delayed for some reason (out and about, waiting for friends etc), I notice it. You'll also notice it because I get cranky!
Lack of sleep:
I don't need 8 hours a night, although that would be nice. I survive quite nicely on 6 hours. Any less than that and guess what? Yep, I get cranky. Watch out when I'm suffering from a bout of insomnia. Not good.
The last thing that makes me cranky? This is new to me. Apparently lack of exercise makes me cranky. For the last month I've been working out pretty much 6 days a week. Either running or swimming or cycling. I somehow managed to hurt my knee, (just a minor injury, nothing exciting) so I took yesterday and today as rest days. Now I'm cranky. I feel blah and gross because I haven't done anything - cleaning, gardening, walking - but that's it.
Previously if I took a day off it never worried me. I never thought I'd be irritable just because I couldn't go for a run or a swim. It's a good thing, right?
Hopefully my knee will be back to normal tomorrow.