I recently have been diagnosed with a low neutrophil count 680mm3. lymphocytes and all other wbcs and rbcs are are all in the normal range and i feel relatively healthy. should i be concerned?

Probably not: There are some people who run perennially low neutrophil counts. Some have what is called cyclic neutropenia in which the variation can be extreme. Would advise checking this again in 6 weeks or if any symptoms develop. Otherwise stay well.

Likely nothing: Dear victorizzo52, this could be likely be nothing. The first thing which needs to be established that is this finding new or has been present for some time. Also is this finding transient/temporary or is a medication or recent infection playing a role. Neutrophils are required to fight infection and a low number might put some people at risk. Would recommend you see a hematologist.

Probably not.: Normal neutrophil count is 1500, no risk of infection until <1000, and severe risk only <500, so 680 is only moderate risk. Causes are many. Sometimes this is transient and related to viral or other illness. Drugs can do this as a side effect. Autoimmune disease can be cause. The absence of problems in rbc or platelets is more reasuring, much less likely to be serious, such as leukemia.