Nipple tenderness most often comes from hormonal shifts tied to your menstrual cycle, but it can also result from friction, skin irritation, pregnancy, breastfeeding complications, medications, or less commonly, an underlying breast condition. Most causes are temporary and harmless, though a few deserve medical attention.
Hormonal Changes During Your Cycle
The most common reason for nipple tenderness is the rise in progesterone that happens after ovulation, during the second half of your menstrual cycle (the luteal phase). Breast tissue contains receptors for both estrogen and progesterone, making it highly responsive to hormonal fluctuations throughout the month. During the luteal phase, progesterone drives the most intense cell activity in the entire breast gland, stimulating the milk-producing tissue to grow and the breast to retain fluid.
The result: swelling, fluid buildup, and pain that peaks near the end of your cycle. Many people notice their breasts feel heavier, lumpier, or asymmetrical during this window. Nipple tenderness is part of this picture, and it typically fades once your period starts and progesterone drops. If you track your symptoms against your cycle and find a clear pattern, hormonal fluctuation is almost certainly the explanation.
Early Pregnancy
Tender nipples are one of the earliest signs of pregnancy, often appearing before a missed period. The sensation is similar to premenstrual breast soreness but tends to be more intense and persistent. Your breasts may feel fuller, the veins more visible, and the nipples darker. Tingling is also common. These changes are driven by the same hormones (progesterone and estrogen), now surging at much higher levels to support the pregnancy. Unlike cyclical tenderness, it doesn’t go away after a few days.
Friction and Chafing
Repetitive rubbing from clothing is a straightforward mechanical cause. Runners know this as “jogger’s nipple,” where thousands of strides create enough friction to leave nipples red, dry, cracked, and sometimes bleeding. Sweat-soaked shirts that cling to the chest make it worse, as does cold weather, which causes nipples to become more erect and vulnerable to rubbing. Cotton shirts are especially notorious because they get heavy when wet and create more drag against the skin.
You can reduce the risk by wearing snug-fitting synthetic fabrics that wick moisture, or by covering the nipples with adhesive bandages or anti-chafe balm before exercise. If chafing has already happened, the area will feel tender to the touch for a few days while the skin heals. Watch for signs of infection like pus or worsening redness.
Skin Irritation and Eczema
The skin on and around the nipple is thinner and more sensitive than most of your body, which makes it a common site for contact irritation. Harsh laundry detergents, scented soaps, lotions, and perfumes can all trigger eczema flare-ups on the nipple and areola. The tenderness in this case usually comes with visible skin changes: redness, flaking, dryness, or cracking.
Switching to unscented laundry detergent formulated for sensitive skin and avoiding fragranced body products that contact your chest often resolves the issue. If you notice the tenderness lines up with a new product you started using, that’s a strong clue.
Breastfeeding Complications
Nipple soreness during breastfeeding is extremely common in the first weeks, usually caused by a shallow latch. But persistent or worsening pain can signal something more specific. Mastitis exists on a spectrum. It can start as an overgrowth of unhealthy bacteria (sometimes called mammary dysbiosis), causing deep aching pain in the breast that radiates to the nipple, along with general breast tenderness. Without treatment, this can progress to inflammatory mastitis, then bacterial mastitis, and potentially an abscess, with increasing pain, redness, and fever at each stage.
Nipple yeast infections (thrush) have traditionally been diagnosed based on visible signs like redness, cracked skin, and swelling around the nipple, along with shooting pain or itching. However, newer evidence suggests the connection between yeast and these symptoms is less clear-cut than once thought, and what looks like thrush may actually be bacterial dysbiosis or another cause of inflammation.
Medications That Cause Breast Tenderness
Several types of medication can cause nipple sensitivity or breast pain as a side effect. Hormonal contraceptives and hormone replacement therapy are the most obvious, but the list extends further. Certain antidepressants (including some SSRIs like fluoxetine and paroxetine), anticonvulsants, acid-reducing stomach medications, and HIV antiretroviral therapies have all been linked to breast tenderness. The mechanism varies, but many of these drugs influence hormone levels or hormone receptor activity. If nipple tenderness started within weeks of beginning a new medication, that connection is worth raising with whoever prescribed it.
Duct Ectasia
Mammary duct ectasia is a benign condition where the milk ducts beneath the nipple widen and fill with fluid and cellular debris. It causes nipple and areola pain along with intermittent nipple discharge that can range in color from white to green, grey, or black. You might also feel a small, tender lump just behind the nipple. It’s most common in people between 45 and 55, around perimenopause, though it can occur at other ages. It’s not dangerous, but the discharge and tenderness can be uncomfortable and worth getting evaluated to rule out other causes.
When Nipple Changes Need Attention
Most nipple tenderness resolves on its own or has an identifiable, benign trigger. But certain combinations of symptoms point to something that needs medical evaluation. Persistent tenderness that doesn’t follow your cycle, nipple discharge (especially if bloody or yellowish), lumps in the breast, skin texture changes, or a nipple that flattens or turns inward all warrant a visit to a healthcare provider.
Paget disease of the breast is a rare form of cancer that starts in the nipple and can initially look like eczema or dermatitis. The key differences: it typically affects only one nipple, doesn’t respond to eczema treatments, and progresses over time with itching, tingling, flaking or crusting skin, and sometimes bloody discharge. A lump in the same breast may also be present. Because it mimics common skin conditions, it’s sometimes misdiagnosed early on, which is why nipple skin changes that don’t improve within a few weeks should be examined.