Breast cancer generally does not directly cause hair loss. In some cases, if it is breast cancer, it may cause anxiety, poor rest, and sleep quality, which might lead to relatively noticeable hair loss. However, hair loss associated with breast cancer mainly occurs during chemotherapy, as it is a common side effect of the treatment. Therefore, apart from chemotherapy, the relationship between breast cancer itself and hair loss is not particularly significant. While some people may experience noticeable hair loss, most do not have obvious hair loss.