Left upper abdominal pain felt as discomfort or fullness, may result from enlarged spleen located in that abdominal area.
The additional symptom would be an early satiety or feeling full even without eating.
Intermittent attacks of severe pain, often in the mid or left upper abdomen and occasionally radiating in a band-like fashion or localized to the mid back, occurring either after meals or independently of meals, lasting at least several hours, could be attacks of pain due to chronic inflammation of the pancreas.
Diarrhea and weight loss are other usual complains.
Upper left abdominal pain could be also due to stomach ulcer, irritable bowel syndrome or other abdominal conditions.
See your physician fore true evaluation!
Best wishes!
Marija