Thanks for your query at DoctorSpring.com
I am Dr.R.K and I am pleased to assist you.
Pain in the upper abdomen on the left most often is due to peptic ulcer disease or pancreatitis. The other causes include left pleural (lining of the lung) and musculoskeletal pain.
I will keep peptic ulcer disease first in the list.
Take Nexium for relief.
Discuss with your gastroenterologist for getting an upper GI endoscopy and a serum amylase and lipase test done.
I hope that answers your question.
Let me know if there are any more questions.