Nipple pain is almost always caused by something identifiable and treatable. The most common reasons are hormonal shifts during your menstrual cycle, friction from clothing or exercise, pregnancy, breastfeeding difficulties, or infections. Less often, medications or skin conditions are the culprit. Here’s how to figure out what’s behind yours.
Hormonal Changes and Your Cycle
If your nipple pain comes and goes on a roughly monthly schedule, hormones are the most likely explanation. Estrogen and progesterone fluctuate throughout the menstrual cycle, and both hormones have a direct stimulating effect on breast tissue. They increase the size and number of ducts and milk glands and cause the breast to retain water. This is why, in the days before your period, both breasts often swell and become tender, painful, or lumpy.
This type of pain is called cyclical breast pain, and it typically affects both sides. It tends to be worst in the week before menstruation and eases once your period starts. Some research suggests that an imbalance in fatty acids within breast cells may play a role by making the tissue more sensitive to these normal hormonal shifts. If you notice that the soreness follows a predictable pattern tied to your cycle, this is very likely your answer.
Friction and Contact Irritation
Nipples are sensitive skin with very little protection. Repeated rubbing from clothing, especially during exercise, causes a well-known problem sometimes called jogger’s nipple. Cotton shirts are particularly notorious for this because they absorb sweat, get heavy, and create more friction as you move. Rough or heavy fabrics make it worse.
Beyond exercise, poorly fitting bras, scratchy materials, or even a new laundry detergent can irritate the nipple and areola. The result looks and feels like a mild abrasion: redness, stinging, and sometimes cracked or raw skin. Switching to moisture-wicking fabrics during workouts, applying a barrier like petroleum jelly before runs, or using a well-fitted sports bra usually resolves it within days.
Pregnancy
Sore nipples are one of the earliest signs of pregnancy, sometimes appearing before a missed period. The sharp spike in hormones during early pregnancy causes rapid changes in breast tissue, and nipple tenderness is often one of the first things people notice. If your pain feels different from your usual premenstrual soreness, is more persistent, or is accompanied by other early pregnancy symptoms like fatigue or nausea, a pregnancy test is a reasonable next step.
Breastfeeding-Related Pain
Nipple pain is one of the most common reasons mothers stop breastfeeding earlier than planned. In one study, nipple pain was the reason for consultation in 36% of breastfeeding-related clinic visits. The causes during breastfeeding break down into a few categories.
Latch Problems
An improper latch is the single most frequent cause of nipple pain during breastfeeding. When a baby doesn’t take enough of the areola into their mouth, the nipple bears the brunt of the suction and compression, leading to cracking, bleeding, and intense soreness. Correcting the latch often resolves the pain within a few feeds. Proper breastfeeding technique has been shown to be one of the most important factors in preventing nipple injury.
Thrush
A yeast infection (thrush) can develop on the nipple, especially after a course of antibiotics. The hallmarks are nipples that look pink, flaky, shiny, or blistered, along with deep shooting pains in the breast during or after feedings. A key clue: thrush often appears after weeks of previously pain-free breastfeeding. Your baby may also have white patches on the inside of their cheeks, tongue, or gums.
Mastitis
Mastitis is a breast infection that causes localized tenderness, warmth, redness, and sometimes flu-like symptoms: fever, chills, body aches, and fatigue. It happens when bacteria enter through cracked nipple skin or a blocked milk duct. Risk factors include a history of mastitis, cracked nipples, wearing a tight bra that restricts milk flow, poor nutrition, smoking, and being overly tired or stressed.
Current guidelines from the Academy of Breastfeeding Medicine recommend conservative care as the first step: ice, over-the-counter anti-inflammatory pain relievers, and feeding the baby on demand rather than trying to “empty” the breast. Aggressive pumping or deep massage can actually worsen inflammation and cause tissue injury. Antibiotics are reserved specifically for bacterial mastitis and should not be used for simple inflammatory symptoms, because they can disrupt the breast’s natural microbial balance and potentially make things worse.
Treating Cracked or Fissured Nipples
For nipples that are cracked, raw, or fissured from any cause, several topical treatments can help. Lanolin is the most widely used option and works as a moisture barrier to protect damaged skin while it heals. Applying a small amount of your own breast milk to the nipple and letting it air-dry is another evidence-based approach. Research has found breast milk effective for both preventing and healing nipple fissures, thanks to its natural emollient, anti-inflammatory, and antibacterial properties. Hydrogel pads and products containing aloe vera or dexpanthenol have also shown positive results, though the evidence base is smaller.
Medications That Cause Nipple Pain
Several common prescription drugs list breast or nipple pain as a side effect. Oral contraceptives and estrogen replacement therapy are among the most frequent offenders, which makes sense given how sensitive breast tissue is to hormonal changes. SSRIs (a common class of antidepressants), certain antipsychotic medications, some blood pressure drugs, and diuretics (water pills) can also cause breast tenderness. If your nipple pain started around the same time as a new medication, that connection is worth exploring with whoever prescribed it.
Mastitis Without Breastfeeding
You don’t have to be breastfeeding to get mastitis. Non-lactational mastitis can happen to anyone. Bacteria can enter breast tissue through cracked or irritated nipple skin, and the resulting infection looks and feels the same: redness, warmth, pain, and sometimes fever. Smoking, nipple piercings, and any condition that causes broken skin around the nipple increase the risk.
Signs That Need Medical Attention
Most nipple pain is benign, but certain symptoms point to something that needs evaluation. A rare form of breast cancer called Paget disease of the breast can mimic common skin irritation. Its symptoms include persistent itching or tingling in the nipple, flaking or crusty skin on or around the nipple that doesn’t heal, a nipple that becomes flattened or inverted, and discharge that is yellowish or bloody. A lump in the same breast may also be present.
Any nipple discharge (especially if bloody or spontaneous), skin changes that don’t resolve within a couple of weeks, pain limited to one specific spot that doesn’t follow a cyclical pattern, or signs of infection like fever and redness all warrant a visit to your doctor. These symptoms don’t automatically mean something serious, but they do need a professional look.