what does "atypical" mean, anyway?

[expert@preeclampsia.org]

What is atypical preeclampsia and how is it diagnosed?

[expert@preeclampsia.org]

I am not sure what atypical preeclampsia is. The syndrome itself is atypical, and even though it often appears with de novo hypertension and proteinuria, other symptoms such as nausea, headache, patient and family history, and abnormal bloodwork are all appreciated when evaluating the likelihood that the patient is experiencing the preeclampsia syndrome.