A breast pump is a tool that assists in expressing breast milk that has accumulated in the mammary glands and can be used when the baby is unable to suckle the breast milk or is unable to suckle the breast milk clean. If a woman is breastfeeding with a large amount of milk, she can use a breast pump to suck out the milk to avoid milk stagnation and reduce the chance of mastitis. If the amount of breast milk is too large and the milk rises, you can also use a breast pump to suck out the milk and reduce the symptoms of breast swelling and pain. Milk is a good medium for mastitis. If a woman has acute mastitis, milk is not drained and stagnates in the breast, which can make mastitis difficult to control. Therefore, at this time, you can use a breast pump to suck out the milk to promote the mastitis to subside. In addition, improper use of breast pump can cause a variety of complications, such as excessive suction force can easily lead to nipple chafing, so women should pay attention to cleanliness and hygiene when using breast pump to avoid secondary infections.