Had cortisone injection 8 days ago in my shoulder . have huge bruise and it hurts worse than before the injection, is this unusual?

Need more info: Are you on blood thinners or high doses of anti-inflammatories like Ibuprofen or aspirin? A huge bruise would be unusual under ordinary circumstances. Was there trauma to the shoulder? Increased pain this late may be the signs of infection. Should be feeling better. Have you had any fever or unusual symptoms, -extreme tiredness or flu-like symptoms. You need to see whoever injected you asap.

No: Depending on the underlying problem, a cortisone injection often does not resolve the pain and can sometimes irritate the shoulder more. That is why a followup appointment is recommended to address this and search deeper for the diagnosis. The bruising is not normal but is not totally unusual. It reflects a blood vessel that was disturbed during the injection. It should resolve on its own.