Blisters on the breast can develop for many reasons. Some blisters are from breastfeeding, while others have nothing to do with breastfeeding at all. The common causes of breast blisters are:

A blockage at the end of a milk ductAn allergic reactionA virusIrritation from rubbing or pressure against your skin

If you get a blister on your breast or nipple, it can be painful and interfere with breastfeeding. Depending on the type of blister, you may even have to stop breastfeeding for a while.

Some blisters appear as a direct result of breastfeeding. Friction and plugged milk ducts are often the source of these kinds of issues.

Friction Blister

Friction blisters are a common problem for people who breastfeed. A friction blister forms when there is constant rubbing or pressure on the same spot on the skin. When you’re breastfeeding, friction blisters can pop up on your breasts, nipples, or areola. Clear fluid or blood can fill a friction blister. If the fluid is bloody, it is sometimes called a blood blister. Possible causes for friction blisters on nipples include:

A poor latch. When your baby is not latched on to your breast correctly, it can cause damage to your breast tissue, areola, and nipple. A poor latch can also cause friction blisters to appear on your baby’s lips. Incorrect use of a breast pump. The improper use of a breast pump can cause irritation and damage to your breasts. When the pump flanges (shields) do not fit you well, or the suction of the pump is set too high, blisters can form. A poor-fitting nipple shield or breast shell. You can get blisters if you use breast shells or nipple shields that constantly rub against your nipple, areola, or the skin on your breast. Improperly fitting nursing bra. If your bra is too big, it could rub against your skin. If it’s too tight, it could put excessive pressure on your breast tissue. Both of these situations can lead to blisters.

If you have a friction blister on your breast, you can continue to breastfeed. It may be painful for you, but a friction blister will not cause harm to your baby. However, if the blister breaks open and the fluid leaks out while you’re nursing, it could change the flavor of your breast milk. Your baby may stop breastfeeding if they don’t like the taste.

Milk Blister 

A milk blister or nipple bleb is a small white or yellow spot on the nipple that blocks the end of the milk duct. It looks like a whitehead pimple. Some people are not bothered by the small blister, but for others, it can be very painful. Milk blisters often go away on their own. Here are some ways to relieve pain and heal more quickly:

Breastfeed often to keep the milk flowing.Rub the surface of your nipple to release the blister.Use a warm compress on the nipple right before breastfeeding.

Talk to your doctor if your milk bleb is painful or doesn’t go away on its own.

Allergens

Poison ivy, poison oak, and poison sumac are plants that can cause an allergic reaction on your skin if you touch them. The reaction can lead to an itchy, red rash with raised fluid-filled blisters. If you get this type of blistery rash on your breasts:

You should not breastfeed You can pump and give the baby your breast milk in a bottle while you have the rash You can begin breastfeeding again once the blisters have healed

Viruses

Certain viruses that cause a rash may also affect the breast. Herpes simplex and varicella are the most common

Herpes Simplex Virus

Active herpes lesions on your breasts can look like small red bumps, fluid-filled blisters, or open sores. They may be itchy or painful. Herpes is dangerous, and even deadly, to infants. Because it can pass to your child through contact with the blisters or sores, you should not breastfeed with active herpes lesions on your breasts. If you think you have herpes you should see your doctor immediately to receive treatment. You should only resume breastfeeding after your lesions dry up and heal and your doctor has given you the thumbs up. In the meantime, you can pump and dump your breast milk to keep up your milk supply.

Chickenpox

Chickenpox (Varicella) is a highly contagious infection that can be spread through the air or by contact. Due to vaccinations and previous childhood immunity, adults in the United States do not often suffer from chickenpox infections. If, however, you do come down with chickenpox while you’re breastfeeding, you can usually continue to nurse your child. By the time you notice the blistery rash, your child would have already been exposed to the virus. If your health care team determines that you need to stay away from your child while you’re contagious, you should still be able to pump your breast milk for your baby.

A Word From Verywell

If you get a blister when you’re breastfeeding, it can be painful. It can also make you worry about whether or not it’s safe to continue to breastfeed. Breast and nipple blisters from breastfeeding are usually friction blisters or a milk blisters, and not something to worry over. But, sometimes a virus or skin reaction can lead to blisters that you have to be more careful about with breastfeeding. When you have a better understanding of the causes and treatment of different types of blisters, you can try to prevent them. Then, if you do get one, you’ll know what to do. If you have any questions about blisters, call or see your doctor. Your doctor can help you identify and treat the blister so you can get back to breastfeeding in safety and comfort.