If it came on sudden I would say look for changes in your direct environment. Something dramatic? Did you maybe hurt yourself? Did you start eating a new foo

If it came on sudden I would say look for changes in your direct environment. Something dramatic? Did you maybe hurt yourself? Did you start eating a new food? Someone pop back up in your life that you thought was gone? That sort of thing. If you can not bisect the issue a sleep study would be better. Medication may help but it may mask the underlying issue. For me it was more of a realization it was my diet. I changed my diet to remove some particular types of foods and now I sleep good. If I eat those foods I sleep like crap. Pop a tums and I am good (it is the upset stomach waking me randomly, so the bad sleep). Everyone has different reasons why. But the top ones are typically stress, injury, or food are a good place to start.