I'm not sure but I am experiencing the same thing. It could be from drinking too much caffeine or a high fat diet (because sometimes your breasts store fat and the glands swell up). Apparently hot sauce can cause it too.
Breast swelling and tenderness don't mean you have cancer though, with cancer that doesn't usually happen. It could also be a hormonal imbalance, or a change in diet (again, fatty foods, caffeine).
I think mine might be because I stopped exercising consistantly due to constipation, and started drinking this laxative tea (probably has a lot of caffeine...) that worked better than I thought. Can laxatives cause breast swelling?
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