Everyone knows about what seems like every woman's battle with pre-menstrual syndrome (PMS).
The pain and agony women go through every month is not one to be made fun of.
But every woman's experience is unique and different - just like the fingers on her hands.
Now, a study from Wakayama Medical University in Japan has revealed that there is a relationship between the length of your index and ring finger and the severity of pains that women can experience during PMS.
The study says it "investigated the relationship between both hands' digit ratios and pre-menstrual symptoms" on 402 19-year-old female students from the university with "no health problems in attending classes".
As you're reading this, put up your right hand.
If the ratio or difference between the lengths of your ring finger and index finger is small, or are almost the same length, then the severity of your PMS is higher.
If your ring finger is significantly longer than your index finger, then you may be able to cope more easily with PMS symptoms.
The ladies took a "Menstrual Distress Questionnaire" where they were assessed on 47 symptoms and their severity, then, 46 of the symptoms were used to score eight specific categories - pain, concentration, behavioural change, autonomic reactions, water retention, negative affect, arousal, and control.
The results suggest that the severity of such pre-menstrual symptoms is associated with pre-natal sex hormones (testosterone and estrogen) exposure.
The study also suggests that women with a longer index finger have longer reproductive periods - from the start of menstruation, called menarche, to menopause - and may have more children.
The study also points out that "one should be cautious in applying our results to the interpretation and prediction of PMS symptoms. We are not sure what percentage of our participants would meet the criteria for PMS because we did not diagnose whether or not the subjects suffered from PMS."