You don’t need to mix water to apply Mannitol externally. It is widely used in clinical practice because of its ability to disperse nodules, reduce swelling and pain, and prevent mastitis while relieving swelling and pain. Patients can use it directly by crushing mannitol and putting it into two cloth bags and placing them on the breasts. The mannitol will melt when exposed to heat, so after 1-2 hours of external application there will be liquid leakage, and the mannitol should be placed in a cool place to dry, not in the sun, because it will melt faster when placed in the sun at higher temperatures. In this case the patient can then change the new cloth bag for external application, and then alternate the use can be, generally external use 3-5 days can play a very good recovery effect.