Written by one female for all females without any other female input.
If you are a stereotypical male, you probably find yourself boggled by the female brain and emotions. You probably also hate it when they cry and you can't make sense of it. By reading the below information you may gain some grasp of such difficult topics.
Most female crying fits fall under one of these categories:
If she is crying due to pain, figure out if it is a sickness pain (headache, stomach ache, etc.) or injury. In case of sickness, consider that women have a high pain tolerance for such things, and look into taking her to a doctor. If it is for injury, assess the situation yourself, ask her opinion, and then act accordingly. I would say to remove the nail that is sticking in her forehead, but if you know anything of first aid, you know that that is not the correct procedure in impalement issues.
Ridiculous Catastrophe (Also known as "No Reason"):
Example: you walk into the kitchen, she is standing over the sink crying. You ask what's wrong and she sobs out, "I dropped my cup of water into the sink and it all spilled!" Your first reaction is probably "What on earth is wrong with this creature?!", so for the sake of your life and this relationship, don't let your first reaction come out of your mouth.
She is not crying because her water spilled. She is crying because as soon as she woke up this morning, she felt crumby. Maybe her head hurts. Maybe she's fighting a cold. Maybe it's that time of month, but whatever it is, her body doesn't feel good. Then she gets up and as soon as she sees a mirror she sighs: she looks just as bad as she feels. Like it or not (and whether we like or not), women tend to care about how they look. From there her morning does not improve: she can't find anything to wear that fixes how she feels about her looks this morning, she drops her hairbrush, she realizes she forgot to complete something for work. Every time something happens she tells herself "It's okay, it's going to be okay, I don't need to freak out about this. It's just going to be a bad day. I can handle a bad day. Don't cry. Don't be emotional. Don't be that girl." And then, with a clank, a dropped cup jars her out of her careful control, and the tears hit. First the tears for the cup, then for the way she feels physically, then the way she looks, then the project she forgot at work. And when you ask her, all that comes out is that she dropped the cup.
How to handle it: As I said, don't let your first reaction slip out! Next step: if there is a mess, help her clean it up. Depending on your relationship with said female, a hug may be appropriate. Whatever you do, do something to make her feel that maybe today doesn't have to be a bad day for the whole day.
This is only a half-truth. We don't cry because we are tired, but, because we are tired, we don't have the energy to put up an anti-crying wall. So, if she is crying because of tiredness, you still need to figure out the real reason. Sorry!
Book or Movie Emotions:
If she is crying because of a book or movie, you really can't help. Realize that she is empathizing and needs to let out the emotions. And take away her books: they are dangerous because they give women ideas and encourage thinking.
If she is laughing so hard that she is crying, I hope you don't see this as a problem. Enjoy the fact that she looks ridiculous doing it, but is carefree enough to do it anyway.
Emotional Topic/Cry Talking:
Ever been in a heated conversation/debate and a female starts crying as she elucidates her point? She hates it more than you do, and wishes she could control it. Just ignore it and do your best to continue the conversation while diffusing the emotions that are blocking her speech patterns. Seriously, she doesn't like that this is happening.
Using Above Crying as Manipulation:
Two possibilities: either she is cruelly manipulative (can't help you there), or she feels that this is the only way you will listen to her. If it is the second. listen now, but also make sure you listen to her before she has to go to this length.
Quietly Crying, Hoping You Don't Notice:
I'm not going to handle this anymore than suggest two things: either something really bad has happened and she doesn't want to ruin your day, or she is depressed.