Brief Answer:
Most probably costochondritis.

Detailed Answer:
Hi.
Thanks for your query, albeit short.
To recapitulate: Female/57 - mild pain - right side - under boob

Please give some additional information for me to assist you further:
- Since when is the pain?
- Any associated history of strain, lifting something, accident, retching/vomiting, direct hit or so that instigated the problem?
- Any other history you would like to share?
- Does the pain increase on deep inspiration or turning the torso in a particular position?
- Does it pain if you put a pressure on this particular point/area?

The commonest reason for such a pain under the breast on one side is usually due to a condition called costochondritis. The rib/s and the muscles are inflamed due to direct or indirect trauma.

I would advise you the following in such a situation:
- Give rest to the area, do not do any activity that will cause strain on the area.
- Do a self-examination and see whether there is any lump or swelling, tenderness.
- Take an anti-inflammatory medicine like Ibuprofen if it suits you,
- Clinical evaluation and related investigations help to confirm or rule out costochondritis and to find out if there is any other possibility and plan the treatment accordingly.
-Stress and/or anxiety does instigate or increase such pains if it is recurrent.

I hope this answers your query, please feel free to give the feedback and ask for further relevant queries if you feel that there is a gap of communication.

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