What is a recurring difficulty in falling or staying asleep called?

This is insomnia: Practicing good sleep hygiene is the first step. Keep your sleep structured, avoid long periods of lying in bed awake, use bed just for sleep and intimacy. Avoid napping during the day. Relaxation and imagery techniques can be very helpful when having trouble going to sleep due to thinking. There are some relatively safe sleep aids that can be taken nightly or just as needed if sleep still bad.