Brief Answer:
Several diagnoses can cause this pain

Detailed Answer:
Hello and welcome to Health Care Magic. Thank you for your question. I understand your concern.

Well, there are a lot of problems that can cause left upper quadrant pain. If this is food intake-related, then the most probable problem lies in the stomach or the first part of the small intestine. Also gastritis (acute or chronic inflammation of the innermost layer of the stomach) may cause this pain, radiating to the central upper part of the abdomen. Assuming this is the case, I would recommend you to try some food intake changes and, also, a one-month course of therapy with a protein pump inhibitor (PPI: omeprazole, pantoprazol etc.). Food to avoid:
- alcohol
- tobacco
- pickles, spicy and grilled food
- chocolate
- caffeine-based beverages (xanthyne derivatives: tea, coffee, energetic drinks)

However, this, as I mentioned, is the most probable diagnosis, based also on your age of 40 years old. But, I would recommend you to run a series of tests, since this is an area that many organs are projected, and the underlying cause could be elsewhere:
- complete blood count (especially to check for white blood cells)
- biochemical analysis (liver and kidney function tests, amylase, glucose, bilirubin)
- plain chest X-ray and plain abdominal X-ray (sometimes inflammation of the lung lining - pleura - can produce such pain; abdominal X-ray to determine if there is gas in the large intestine - the descendent part)
- abdominal ultrasound - to check for cysts, masses or other abnormalities in the area
- urinalysis
- pregnancy test - especially in the beginning period of the pregnancy, this is where the pain is localized
- upper gastro-intestinal endoscopy (optional - if the above described treatment is not associated with a symptom relief).
I understand there are a lot of tests to take, but, as I mentioned above, this is an area where a lot of organs and organic systems are projected, and no diagnosis can be ruled out without these tests, especially when the only symptom is pain in this quadrant of the abdomen.

I hope I was helpful with my answer. Feel free to ask follow-up questions, as I am happy to help. Please rate the answer, if you do not have further questions.

Wish you a good health.

Kind regards,
Dr. Meriton

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