<s>[INST] I had a cortisone injection in my shoulder on Thursday, I am experiencing severe pains on my lower back , from back of neck & lower, I break out of sweat every now and then. Have seen my GP on Sunday, GP has given antibiotics as I have got the flu too. I also have massive head aches. [/INST] Hello, Thanks for your query. The problem you are experiencing is called Cortisone flare, which is a brief increase of pain for 1 to 3 days. It occurs when the cortisone crystallizes after injection. Rest, ice, and over-the-counter pain medicines, such as ibuprofen and acetaminophen, can provide relief. Look for signs of infection Luke redness at injection site, fever, chills etc. if you have any consult your disc otherwise the pain will soon alleviate. I do hope that you have found something helpful, and I will be glad to answer any further query. Take care </s>