It seems from the history that your 5 year old son is having fever
, headache, vomiting
and diastolic blood pressure of 34.
Fever headache and vomiting indicate infection.
Diastolic blood pressure of 34 indicates hypotension
as a result of dehydration
caused by vomiting.
Hence this requires correction of the dehydration by using fluids.
Since diastolic blood pressure is low urgent intervention is required.