Blood test

[unhappy13]

My son recently had his appendix out during his time in hospital he had a number of blood tests done nothing came back whilst we were in , I had a call yesterday from the doctors asking for a repeat blood (receptionist didn't know why) so took him today but then later when post came I had letter from hospital saying his white blood cells were low , and if the same on next test to be transferred to paediatrics , worried as when I've googled .. first thing that comes up is Cancer and bone marrow 😐 ... I have low red cells (anemia and b12) but can't find much out for low white ... worried

There are lots of things that can cause a low white cell count in children. They range from a specific virus to a side effect of some antibiotics to more serious conditions. The most likely is something transient and not serious butbthey obviously have to rule out the most serious conditions first. A bit like ruling out a heart attack before you tell someone with chest pain that it’s indigestion.
Get the bloods done but try not to panic. Interestingly low B12 can also cause a low white cell count but is probably unrelated.