The nurse is assessing a client who is 2 weeks postpartum. The nurse would be concerned about mastitis if which of the following were noted? Select all that apply.

Choice A rationale Urinary frequency is not a typical symptom of mastitis. This symptom is more commonly associated with urinary tract infections or a normal postpartum physiological response due to the increased diuresis that occurs as the body eliminates excess fluid from pregnancy. Choice B rationale Flu-like symptoms such as fever, chills, malaise, and myalgia are systemic inflammatory responses often accompanying mastitis. These symptoms are caused by the body's release of cytokines in response to the bacterial infection, leading to a widespread systemic reaction. Choice C rationale Unilateral breast tenderness is a classic localized sign of mastitis, indicating inflammation and infection within the affected breast tissue. This localized pain is a direct result of tissue damage and the inflammatory cascade triggered by bacterial proliferation. Choice D rationale Unilateral breast erythema, or redness, is a cardinal sign of inflammation and infection in mastitis. This symptom is caused by vasodilation of local blood vessels and increased blood flow to the infected area, a key component of the inflammatory response. Choice E rationale Uterine tenderness is not a symptom of mastitis. Uterine tenderness, particularly with foul-smelling lochia and fever, is indicative of a postpartum uterine infection, such as endometritis, which is a different clinical condition affecting the reproductive tract. Choice F rationale Bilateral breast firmness is not a typical symptom of mastitis. This finding is more consistent with bilateral breast engorgement, which is a physiological process characterized by venous and lymphatic stasis, and not a localized bacterial infection.