Clinophobia is a condition in which a person has an abnormal fear of going to bed or falling asleep. It is also known as sleep anxiety, somniphobia, or hypnophobia. There are several other words that can be used as synonyms for clinophobia such as noctiphobia, which is a fear of the night, or cacomorphobia which is the fear of going to bed. Nyctophobia encompasses more of a fear of the dark, but can also involve a fear of going to bed as part of not wanting to deal with the darkness. Other more general terms that could be used as synonyms might include anxiety, fear, phobia, or even insomnia, which is often closely associated with sleep anxiety.