If your lady has been cranky for no reason lately, your first reaction may be that she is PMS'ing...again. Maybe she's not getting enough sleep, maybe she's not getting enough sex or maybe she's just a plain old bitch. Once you get beyond all of that, there may actually be a medical reason for her short temper. It could be that she is low on electrolytes or possibly her iron levels are deficient. Time for a doctor check-up.