What’s wrong with a hard lump in a newborn’s breast at 20 days?

A newborn with a hard lump in the breast at 20 days may have a mild hyperplasia caused by estrogen in the mother.
There are some newborns who are born with some hard lumps in their breasts, which is clinically known as pseudobreasts. It is usually due to estrogen in the mother’s body during pregnancy passing through the placenta to the fetus. And estrogen can cause breast development, which can lead to hard lumps in the breasts after birth.
If there is no redness or swelling at the lump, and the baby has no pain when palpated, there is no need to treat the lump, and the lump will disappear on its own as the hormone is metabolized with increasing age.
In addition, you need to pay attention to the local hygiene of the baby’s breast, do not squeeze the lump with your hands to avoid infection, etc. You can give your baby appropriate water.