may be due to some stress,anxiety
,and tension.instead of going for sleeeping pills try all these methods first, and use drugs only as a last resort. The decision, of course, is yours.
1)take warm bath which will help relax your body.dont overdo it.
2)drink warm milk 20mins before bed time
3)listen to soft music
6)physical exercise during day time
7)balanced diet and meditation
after trying all these method,if you fail to get sleep than you can consult nearby psychiatrist