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Stomach gas or bloating is caused mainly because of air swallowing known as erophagia means we engulf air during chewing,speaking, drinking etc.air goes inside the stomach.
Puffy and bigger nipples or areola could be related to this but it can be commented only after the visual inspection of the area to rule out any local pathology.
The medical causes of stomach bloating
could be irritable bowel syndrome
,bowel obstruction etc
You do regular exercises and if still having abdominal bloating
or distension then u should start some medication like proton pump
inhibitors,avoid excess carbohydrates and fatty foods, avoid oily and spicy foods.
If you still have these problems then u should go to gastroenterologist who can order some blood works,ESR,abdominal ultrasound and upper GI endoscopy to treat underlying cause.
Treatment generally will depend upon the cause.