Hello and welcome to Healthcare Magic. Thanks for your query.
It is unlikely that the headache is related to the possible "thrombo-phlebitis" (clotting and inflammation of the vein) which had happened 4 days ago. It could be due to a sinustis due to the cold or some other independent cause.
However, if the headache is becoming severe, with associated symptoms like vomiting
, problems in vision, confusion, drowsiness
, weakness or numbness
of any part of the body, then these are danger signs and you need to see a doctor immediately.
Also, if you are developing an increase in swelling, redness
or pain over the injection site or fever
, then you have to seek urgent medical attention.
Wish you all the best.
Dr. Sheeba Stephen
Emergency Medicine Consultant