Brief Answer:
Could be due to unbalanced estrogen levels in the body

Detailed Answer:
Hi,
Welcome to Healthcare Magic.
I am Dr Ramadevi Wani. I will be answering your concerns.

Since you are postmenopausal, unbalanced estrogen levels can cause sore breasts and nipple. This is the commonest cause.
Are you on any medications like antidepressants, cimetidine etc.? These can cause sore breast and nipple
In your case it can also be due to:

1. Are you a fitness freak? Friction with bra from running and sports can initiate inflammation and cause sore nipples and breast. Therefore if you are a sports person, wear well supported correct size sports bra while playing. Use synthetic fabric bra rather than cotton.
2. Injury or unusual pressure on the chest muscles ( due to push ups, lifting heavy objects etc)
3. Nipples are very sensitive. Allergy to shower gel/ lotions/ fabric which can cause inflammation in the nipples resulting in sore breasts and nipples
4. Infection. In this case nipples will usually show redness.
5. Increased prolactin hormone level or reduced functioning of thyroid gland can cause this problem.
Do you feel any lump in the breast? Is there is redness/discharge from the nipple? Is there any family history of breast /ovarian/colon cancer?
If your answer is yes then I would be concerned about breast cancer. To put your mind at ease I advise you to have your breasts examined by surgeon/Gynecologist/GP. In this scenario it is wise to do a mammogram.
If the answer is no I advise you to:
- wear well supported bra even while sleeping.
- Cut down on caffeine/alcohol ( if you are drinking)
- Use hot compresses to relieve pain
- Ibuproofen 400 mg twice daily for 2-3 days
If the pain is not relieved within few days, you must consult doctor. Based on examination she may ask you to do hormone tests.
I hope this helps.
If you have any further queries do consult me through Healthcare Magic. I will be happy to answer.

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