Persistent nipple pain is NOT caused by neural or central nervous system sensitisation

What causes persistent nipple pain?

For too many breastfeeding women, nipple pain goes on and on. This can occur in the absence of visible epithelial cracks and damage, or even visible redness or inflammation. Guidelines often define 'persistent nipple pain' in lactation as nipple pain that goes on for more than two weeks.

Persistent nipple pain results from both superficial and deep tissue injury, due to exposure to the repetitive and mechanical microtrauma of highly focussed stretching and bending forces. The dermis of the nipples are densely innervated with nerve endings. Skin and deep tissues exposed to repetitive mechanical trauma release histamine and a range of pain-inducing pro-inflammatory factors.

Persistent nipple pain is often a result of our health systems' blind spots

Current guidelines for the management of persistent nipple pain are built on the assumption that the woman has had the best possible fit and hold intervention possible, and that positioning problems are no longer relevant. But there is usually so much that hasn’t been done to eliminate the mechanical effects of high and concentrated stretching loads on your nipple and breast tissue!

If a woman is in pain, she needs the mechanical stretching load better distributed over a larger surface area of her nipple and breast tissue inside baby's mouth, so that the vacuum expands the breast tissue evenly and opens up ducts, without subjecting any specific part of the nipple epithelium to a very concentrated shearing and stretching load.

Chronic mechanical trauma may also be perpetuated by pumping.

Persistent nipple pain is often misdiagnosed and wrongly treated

Persistent nipple pain in breastfeeding is highly overmedicalised. You can read more about this here.

• If you have persistent nipple pain, you might find that you are diagnosed with thrush, which is rarely a cause of nipple pain and inflammation since candida albicans, which causes thrush infection, is a normal part of your milk, your nipple skin, and baby's mouth microbiomes. You can find out when it might be thrush thrush here.

• If you have persistent nipple pain, you might also find that your baby is diagnosed with suck or tongue movement dysfunction, or with tongue-tie. You can find out about these diagnoses here.

Most concerningly of all to me, persistent nipple pain is often wrongly attributed to central nervous system sensitisation, also referred to as neuropathic pain, hyperalgesia, or allodynia. If the term allodynia is used correctly, then nipple pain, whether new or ongoing, often does show signs of allodynia. This is because allodynia means that a very large touch results in a pain response that seems disproportionate (e.g. from water touching your nipples in the shower or the bedsheet touching your nipples). It's not because the brain wiring has started to overamplify the pain sensation: it is because there is very high density of pain receptors (called nociceptors) in the lower layer of your nipple skin and the acute pain sensation from even very light mechanical contact can be severe.

That's not to say that our emotional wellbeing, stress levels, and environment don't impact upon our perception of pain from acute nipple tissue damage and inflammation - they do. But using these diagnoses of neuropathic pain, hyperalgesia, and central sensitisation for your ongoing nipple pain fail to understand the International Association for the Study of Pain's use of these terms, and might result in you being prescribed unnecessary medications, which have no evidence of usefulness for nipple pain and which run the risk of side-effects.

Most women's persistent nipple pain when they are breastfeeding or pumping is due to repeated mechanical microtrauma. Breastfeeding women know this. Once you stop breastfeeding, your persistent nipple pain will resolve, because your nipple will no longer suffer acute tissue damage from this repetitive stretching and bending microtrauma.

What really matters is that you have the help you need to remove the underlying cause of acute tissue damage and inflammation.

Recommended resources

Why persistent lactation-related nipple pain is not due to hyperalgesia, neuropathic pain, or central sensitisation