Could csf leak under under the skin causing very baggy eyes. started all of sudden and i get very bad headaches in the upright position. better when i lye down. i have hydrocephalus and had a etv. ?

Low-pressure headache: You're certainly describing a low CSF pressure syndrome. Please return the physician who did lumbar puncture on you and discuss options such as a "blood patch." commonly this procedure can help it if your headaches are being caused by this phenomenon.

Probably not: CSF leakage typically occurs through the ears or nose, not as bags under the eyes. Lack of sleep, fatigue etc can lead to fluid accumulation under the eyes- this is not csf. Unless you've had recent brain surgery- highly unlikely.

I am not aware of: Baggy eyes as a symptom of a CSF leak. Usually such leaks are via the ears or nose (clear fluid, perhaps after a cough or sneeze), and usually soon after a surgical procedure or significant head trauma. Did you have a recent lumbar puncture? If so, perhaps the positional headache relates to that. Please see your neurosurgeon or neurologist.