Pregnancy armpit swelling is often for the following reasons: first, parametrial hyperplasia, people will have many breasts in the evolutionary process, but the other breasts will gradually degenerate, leaving only the two breasts in front of the chest, with the rise of hormone levels in the body, the degenerated breasts will grow again, especially the armpit breasts, which generally do not have to worry too much, with the postpartum hormone levels of secretion decline, the enlarged parametrial breast can gradually subside, but if However, if there is no significant relief or significant pain, surgery can be performed to remove the treatment. Secondly, swollen lymph nodes are often caused by bacterial or viral infections and need to be clarified by color Doppler ultrasound and blood tests in the armpit. Third, the body surface abscess or subcutaneous cyst formation, which need to go to the hospital in time to check the ultrasound for clarification. In short, if the underarm continues to be enlarged, you need to go to the hospital in time to clarify the cause.