Cries, making emergency call about blood group (4)
I believe the answer is:
sobs
'cries' is the definition.
(sobbing is a kind of crying)
'emergency call about blood group' is the wordplay.
'emergency call' becomes 'sos'.
'about' indicates putting letters inside.
'blood group' becomes 'b' (B is an example).
'sos' going around 'b' is 'SOBS'.
'making' is the link.
(Other definitions for sobs that I've seen before include "Weeps heavily for boss" , "showing distress" , "convulsions" , "cries uncontrollably" , "Weeps noisily" .)