Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
After leaving, seek emergency help for severe breathing difficulty, chest pain, collapse, confusion, blue or grey lips, or swelling of the face or tongue.
And for anyone, someone who:
During a transfusion, tell staff immediately about any new symptom.
Do not wait for it to settle.
Contact your healthcare team urgently for fever, shaking chills, worsening shortness of breath, dark urine, yellow skin or eyes, very little urine, a spreading rash, or increasing back or chest pain.
These problems can occur hours or days later.
Seek advice sooner for IV-site bruising that is enlarging, painful, hot, or swollen.
Contact the team if expected symptoms are not improving, tiredness is worsening, or you have questions about follow-up tests.
Every sign above is quoted from the sofidex article on Blood transfusion. If you are not sure, err upward — it is always reasonable to be checked.