Nipple pain is extremely common and almost always tied to something benign, like hormonal shifts, friction, or skin irritation. The most frequent cause is cyclical breast pain linked to the menstrual cycle, but pregnancy, breastfeeding, medications, infections, and even your laundry detergent can all be behind it. Here’s a breakdown of the most likely reasons and what to look for.
Hormonal Changes During Your Cycle
The single most common cause of nipple and breast pain is your menstrual cycle. In the second half of your cycle (after ovulation), estrogen and progesterone levels shift. Some people have a lower ratio of progesterone to estrogen during this phase, which can make breast tissue swell and nipples feel tender, sore, or hypersensitive. The hormone prolactin may also play a role.
This type of pain is called cyclical mastalgia. It typically shows up in the week or two before your period, affects both breasts, and fades once your period starts. You might notice it as a dull ache, a sharp sensitivity to touch, or general soreness that radiates from the nipple into the surrounding breast tissue. Stress can amplify it because stress hormones interact with the same pathways that drive cyclical breast pain.
If your nipple pain follows a predictable monthly pattern, hormones are the most likely explanation. Tracking the timing for two or three cycles can help confirm it.
Early Pregnancy
Sore, tender nipples are one of the earliest signs of pregnancy. Hormonal surges cause increased blood flow and tissue changes in the breasts, and this can begin as early as two weeks after conception. Most people notice breast changes between weeks four and six. Your nipples may feel swollen, sensitive to the lightest touch, or almost bruised. The areola (the darker area around the nipple) often darkens or gets larger during this time too.
If your period is late and your nipples have been unusually sore for more than a few days, a pregnancy test is a reasonable next step.
Breastfeeding-Related Pain
Nipple pain during breastfeeding is common, especially in the first few weeks as your body adjusts. A poor latch, where the baby doesn’t take enough of the areola into their mouth, is the most frequent culprit. But two infections also target nursing parents specifically: mastitis and thrush.
Mastitis
Mastitis is a bacterial infection in breast tissue. It comes on fast and feels like the flu: fever, chills, body aches, nausea, and fatigue. The affected breast will feel warm or hot to the touch, look pink or red, and feel tender. You might notice a yellowish nipple discharge. It usually hits one breast, not both.
Thrush
Thrush is a fungal infection caused by yeast. It looks and feels quite different from mastitis. Your nipples may turn pink, flaky, shiny, or cracked. The pain tends to be a persistent soreness that lasts beyond the first few days of breastfeeding, or it appears after weeks of pain-free nursing. Many people describe shooting pains deep in the breast during or after feedings. A telltale sign: white patches inside your baby’s cheeks, tongue, or gums. If you see those spots and your nipples are sore, thrush is very likely.
Friction and Chafing
Sometimes called “jogger’s nipple,” friction-related pain happens when clothing rubs repeatedly against your nipples during physical activity. Runners, cyclists, and anyone doing prolonged exercise are vulnerable. Cotton shirts are a common offender because they absorb sweat, get heavy, and cling to skin. The result can range from mild tenderness to raw, cracked, or even bleeding nipples.
Switching to lightweight, moisture-wicking fabrics helps significantly. A snug-fitting shirt reduces the back-and-forth fabric movement that causes chafing. A well-fitting sports bra adds another layer of protection. Before a run, you can apply petroleum jelly or a lubricating balm directly to your nipples, or place adhesive bandages over them as a physical barrier. If chafing has already happened, an antibacterial ointment can prevent infection while the skin heals.
Skin Irritation and Eczema
The skin on and around your nipples is thinner and more sensitive than the skin on most of your body, which makes it a common spot for eczema flare-ups and contact reactions. Nipple eczema shows up as an itchy, dry, sometimes weepy rash on the nipple or areola.
Common triggers include harsh laundry detergents, scented soaps or lotions, certain fabrics, and perfumes. Sweat trapped under a bra can also cause irritation. Some people develop flare-ups from food allergies or other allergens that trigger a broader immune response. If you’ve recently switched detergents, body products, or bra materials and your nipples are suddenly itchy and irritated, the new product is a likely suspect. Switching back or choosing fragrance-free alternatives often resolves it within a few days.
Medications That Cause Breast Pain
Several categories of prescription medications list breast or nipple pain as a known side effect. These include oral contraceptives and hormone replacement therapy (which shift estrogen levels directly), certain antidepressants (particularly SSRIs like fluoxetine), some antipsychotic medications, certain blood pressure drugs, and diuretics (water pills). If your nipple pain started shortly after beginning a new medication, the timing is worth mentioning to your prescriber. In many cases, adjusting the dose or switching to a different medication resolves the issue.
Paget’s Disease of the Breast
This is the rare cause that’s worth knowing about because it can look like a common skin problem. Paget’s disease of the breast is a form of breast cancer that starts in the nipple. It mimics eczema or dermatitis closely enough that it sometimes gets treated as a skin condition for months before being correctly identified.
The key differences: Paget’s disease typically affects only one nipple, not both. Symptoms include persistent itching, tingling, or redness of the nipple or areola, along with flaking, crusty, or thickened skin. The nipple may flatten or turn inward over time, and you might notice a yellowish or bloody discharge. Eczema, by contrast, usually responds to moisturizers and avoiding irritants. Paget’s disease does not improve with those measures.
If skin changes on one nipple persist for several weeks despite basic treatment, or if you notice discharge, a flattening nipple, or a lump in the breast, those are signs that warrant medical evaluation. Diagnosis involves imaging (mammogram, ultrasound, or MRI) and a biopsy of the affected skin.
Signs That Need Medical Attention
Most nipple pain resolves on its own or with simple changes like switching products, adjusting your bra, or waiting out your menstrual cycle. But certain combinations of symptoms point to something that needs a professional evaluation:
- Persistent pain that doesn’t follow a cyclical pattern and doesn’t improve over several weeks
- Nipple discharge that isn’t breast milk, especially if it’s bloody or comes from only one side
- Visible changes to your nipple’s shape, color, or texture, like flattening, inversion, or crusting
- A lump anywhere in the breast
- Fever or feeling unwell alongside breast or nipple soreness, which suggests infection
- Skin changes on or around the nipple that don’t respond to basic skincare within a few weeks
Any one of these on its own is reason enough to get checked. In most cases, the answer will still be something straightforward and treatable, but catching the occasional serious cause early makes a meaningful difference in outcomes.