An unduly timid or anxious person, as in He's a real nervous Nellie, calling the doctor about every little symptom. This term does not allude to a particular person named Nellie; rather, the name was probably chosen for the sake of alliteration. [Colloquial; c. 1920]
An individual suffering from extreme agitation or worry, as in Pat was a nervous wreck until her mother arrived at the wedding. This expression is nearly always used hyperbolically. [Colloquial; c. 1900] Also see basket case.