CSF - 85% Lymphs

  I had a lumbar puncture performed after a sudden and severe headache which was my first at 46.  The csf revealed 85% lymphs and i am an oncology nurse and this sounds alarmingly elevated to me.  I had no infection to my knowledge and my neurosurgeon made no reference to this lab result.  Can you give me the normals and what you feel could contribute to this.....thank you so much for your commitment to your field.  Incidentally i was dx'd with a SAH and wonder if the high number of lymphs could represent a traumatic tap vs. a true SAH.  Again, thank you for your time and response.  
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In general, there should be more lymphs than polys in CSF.
There is an important piece of data missing. The percentage of lymphs/polys/etc is meaningless unless it is in context of the clinical picture and the rest of the CSF data, particularly the total WBC count.
If the total WBC count is normal (from lab to lab, varies from <3 to <5 or about there), then you don't even need to look at the percentages. Often, I'll see a report of 1 WBC and a differential is quoted based on fewer than 100 cells spun down in the whole sample! I just ignore the information.
Obviously, if the WBC count is elevated, then the differential may be relevant. For example, 500 WBCs with too many polys in the setting of acute fever, headache, and stiff neck, makes one think of bacterial meningitis. But even during the course of an acute illness, the relative amounts of polys and lymphs will evolve.
The question of SAH is interesting. There, the WBC count (and thus the differential) is less relevant than the RBC count. Indeed, you can have artifactual changes in WBC count (and glucose and protein, for that matter) when there is a lot of blood in the CSF. Deciding between traumatic tap and SAH is sometimes difficult, and it is up to the clinical judgement of the ER doctor and/or consultant (neurosurgeon, in your case) to put all the pieces together to figure it out.
One editorial comment, in general (which is relevant for many doctors as well as patients). The most important part of the diagnosis is the history and physical exam. All lab test results must be put into the context of clinical questions raised by the history and exam. I hope this helps. As you know, this information is posted for your medical education. Specific comments regarding your diagnosis, prognosis, and treatment options must come from your doctor after appropriate evaluation. CCF MD mdf.