Nipple pain has a wide range of causes, from hormonal shifts and friction to infections and skin reactions. Most of the time it’s temporary and tied to something identifiable, like your menstrual cycle, a poorly fitting bra, or a new laundry detergent. Less commonly, persistent nipple pain can signal something that needs medical attention.
Hormonal Shifts Before Your Period
The most common reason for sore nipples is the rise and fall of estrogen and progesterone throughout your menstrual cycle. Nipples are most likely to be sore in the week leading up to your period, during the luteal phase, when progesterone peaks and causes breast tissue to retain fluid and swell slightly. This tenderness usually fades once your period starts and hormone levels drop.
Perimenopause can also trigger nipple soreness because hormone levels become more erratic during this transition. If you’re in your 40s or early 50s and noticing new or worsening breast tenderness, fluctuating hormones are a likely explanation.
Early Pregnancy
Nipple sensitivity is one of the earliest signs of pregnancy, often showing up around weeks two to four. Rising estrogen and progesterone stimulate the development of milk ducts and increase blood flow to breast tissue, making nipples noticeably more tender. Many people describe this as a sharper, more persistent version of premenstrual soreness. It’s common for this sensitivity to ease after the first trimester as your body adjusts to the new hormone levels.
Breastfeeding Problems
Some nipple soreness in the first days of breastfeeding is normal, but pain that persists beyond the initial latch or gets worse over time usually points to a specific problem.
Poor Latch
When a baby doesn’t latch deeply enough, the nipple gets compressed against the hard palate instead of drawn toward the back of the mouth. This causes cracking, blistering, and sharp pain with every feeding. A lactation consultant can usually correct latch issues in one or two sessions.
Thrush
A yeast infection called thrush can develop on the nipples, especially after a course of antibiotics. Signs include pink, flaky, shiny, or cracked nipples, along with a deep aching or shooting pain during or after feedings. Your baby may have white patches on the inside of their cheeks, tongue, or gums. Both parent and baby need to be treated at the same time to prevent passing the infection back and forth.
Mastitis
Mastitis is a breast infection that causes warmth, redness, and tenderness, often alongside flu-like symptoms: fever, chills, body aches, and fatigue. You may notice yellowish discharge from the nipple. Mastitis typically develops when a milk duct becomes blocked and bacteria enter through cracked skin. It requires prompt treatment to prevent an abscess from forming.
Friction and Chafing
Repetitive rubbing from clothing is a surprisingly common cause of nipple pain, especially in runners. Each stride shifts your shirt slightly across your chest, and over the course of a long run, that constant motion can chafe the skin raw. Sweat-soaked shirts stick to the chest and increase friction. Cold weather makes nipples more erect and more vulnerable to rubbing.
Cotton shirts are particularly notorious for this because they absorb sweat, get heavy, and cling. Switching to lightweight, moisture-wicking fabrics that pull sweat away from the skin can make a significant difference. A snug-fitting shirt reduces the back-and-forth movement that causes chafing, and a supportive sports bra adds another layer of protection. For extra insurance, you can apply petroleum jelly to your nipples before exercise or cover them with adhesive bandages. Specialized anti-chafe balms and nipple covers designed for athletes also work well.
Contact Dermatitis and Skin Reactions
Nipple skin is thinner and more sensitive than the surrounding breast, making it especially reactive to chemical irritants. Laundry detergents are a common culprit. They can leave behind residues on clothing that sit directly against nipple tissue for hours. The potential allergens in detergent include fragrances, preservatives (particularly a class of chemicals called isothiazolinones), surfactants, dyes, and brighteners. Even products marketed as “gentle” or “safe for sensitive skin” can contain surfactants like alkyl glucosides that cause reactions in some people.
Beyond detergent, other triggers include scented soaps, body lotions applied to the chest, fabric softener sheets, and synthetic dye residues in clothing. If your nipple pain started around the same time you switched a product, try eliminating it for a couple of weeks to see if the irritation clears.
Nipple Vasospasm
Vasospasm happens when blood vessels in the nipple suddenly constrict, cutting off blood flow temporarily. It causes intense burning or throbbing pain, often triggered by cold air exposure. You may see the nipple or its tip turn white, then shift to blue or purple before returning to its normal color. The pattern is similar to what happens in fingers and toes with Raynaud’s phenomenon.
Vasospasm is more common in people who are breastfeeding, especially if there’s an underlying latch problem or cracked skin. Smoking worsens it because nicotine constricts blood vessels further. Keeping your chest warm after feedings, avoiding cold air exposure on bare nipples, and addressing any latch issues are the main strategies for managing it.
Medications That Cause Nipple Pain
Several types of medication list breast or nipple pain as a side effect. Oral contraceptives and estrogen replacement therapy are the most obvious, since they directly alter hormone levels. But other, less expected medications can also be responsible, including certain antipsychotic drugs, some antidepressants (particularly SSRIs like fluoxetine), water pills, and the heart medication digitalis. If nipple pain started shortly after beginning a new medication, that timing is worth noting and discussing with your prescriber.
Mammary Duct Ectasia
This condition occurs when a milk duct beneath the nipple widens and its walls thicken, sometimes trapping fluid. It most commonly affects people between ages 45 and 55, during perimenopause, though it can also develop after menopause. Symptoms include nipple tenderness, a thick discharge that can be white, yellow, green, or black, and sometimes a small lump near the affected duct. The nipple may also pull inward. In many cases, duct ectasia causes no symptoms at all and resolves on its own. If the blocked duct becomes infected, it can progress to mastitis with redness, swelling, and fever.
Signs That Need Medical Evaluation
Most nipple pain is benign, but certain patterns warrant a closer look. Paget’s disease of the breast is a rare form of cancer that initially looks like eczema or dermatitis on the nipple. The key differences: flaking, crusty, or thickened skin on or around the nipple that doesn’t respond to standard skin treatments, a nipple that becomes flattened, and discharge that is bloody. A lump in the same breast may also be present. Because Paget’s disease closely mimics common skin conditions, it’s sometimes misdiagnosed for months.
In general, nipple pain that affects only one side, lasts more than a couple of weeks without an obvious cause, comes with bloody or spontaneous discharge, or is accompanied by skin changes like puckering, dimpling, or persistent redness is worth getting evaluated. An imaging study can typically rule out anything serious quickly.