ANDY'S ANSWER: PMS stands for Pre Menstrual Syndrome. Really, it's a variety of things that you may notice in the week or weeks ahead of your period. These can be physical or emotional changes brought on by the hormones in your body.
For instance, physical symptoms may include tenderness in the breasts, bloating or gas, cramping, headache, constipation or diarrhea, increased sensitivity to light or noise, or increased appetite or food cravings.
Emotional changes could be irritability, depression, mood swings in general, difficulty with concentration, tiredness, feelings of anxiety or guilt and sleeping issues.
Keeping a daily diary about your health and body in general is a good idea. You should document when you start noticing physical and emotional changes as well as when your periods start and end. If you use a computer word program as your diary, you can later plug in a key words like "Hyper" for instance and see how often it comes up and where it comes up in relation to your menstrual cycle.
Understanding the changes that occur in you around your periods will help you manage especially the emotional symptoms so they do not escalate to extremes.