Out of the many causes of nervousness few are constant worries, irritation, mental tension, mental exhaustion, lack of sleep, protracted indigestion, unfavorable circumstances, deviation from the spiritual and religious norms and values, lack of contentment, whims, doubts and insecurity etc.
First of all, one must learn to be contented and should develop the habit of leaving one’s affairs to God. Leaving things to God does not mean that man should stop striving. Right approach is that after doing your part of the job leave the results to God
As a treatment for nervousness, recite the following once
اَلْرَّضَاعَتْ عَمَا نَوِیْلْ
and blow upon a half-cup of water and drink this water. This should be done early in the morning before sunrise.