Which symptom may indicate the presence of a plugged milk duct?

The presence of swollen lymph nodes can indeed indicate a plugged milk duct, particularly when associated with breastfeeding or lactation issues. When a milk duct becomes obstructed, it can cause localized inflammation and lead to the swelling of nearby lymph nodes as the body responds to the inflammation. This could manifest in discomfort in the breast area and can be accompanied by other symptoms linked to breast issues, such as redness or tenderness.

The other symptoms listed, including pain during urination, fever-like symptoms, and episodes of vomiting, are not typically associated with a plugged milk duct. Pain during urination suggests a urinary tract issue, while fever-like symptoms might indicate an infection elsewhere in the body rather than a localized breast issue. Episodes of vomiting can be indicative of gastrointestinal issues or other unrelated problems. Therefore, swollen lymph nodes are the most relevant symptom to consider in the context of a plugged milk duct.