Do you thrash around in bed or act out dreams when you are deeply asleep? Sometimes, your spouse will notice or will want to move to another bed. Sudden movements during sleep may be a sign of Parkinson's disease.
What is normal? It is normal for everyone to have a night when they 'toss and turn' instead of sleeping. Similarly, quick jerks of the body when initiation sleep or when in lighter sleep are common and often normal.