A pimple on your nipple is almost always harmless. The most common causes are clogged pores, irritated hair follicles, or naturally occurring glands in the skin of your areola that have become more noticeable. In rare cases, a bump that looks like a pimple can signal an infection or another condition worth checking out.
Montgomery Glands: The Most Likely Explanation
The small bumps most people notice on their nipples or areolas aren’t pimples at all. They’re Montgomery glands, specialized oil glands embedded in the darker skin around your nipple. Each areola can have anywhere from zero to 40 of these tiny bumps, with most people having about 10 to 15 per side. They release an oily substance that lubricates and protects the delicate nipple skin, maintains an acidic pH to ward off bacteria and yeast, and (during breastfeeding) produces a scent that helps babies find and latch onto the nipple.
Montgomery glands are often barely visible. But they can swell and become more prominent during hormonal shifts, pregnancy, or breastfeeding, making them suddenly noticeable for the first time. Occasionally one of these glands gets blocked, and the resulting bump looks almost identical to a whitehead. It typically resolves on its own without treatment.
Actual Acne on the Nipple
Your nipple and areola have pores and hair follicles just like the rest of your body, which means they can develop genuine pimples. Dead skin cells mix with sebum and plug a pore, creating a whitehead or small red bump. Hormonal fluctuations, particularly around certain points in the menstrual cycle, make this more likely. A deep, persistent form of acne can also cause reddish bumps on the nipple that never come to a head, though this is uncommon.
Ingrown hairs are another frequent culprit. Fine hairs grow around the areola in most people, and when one curls back into the skin, it creates a raised, sometimes painful bump that’s easy to mistake for a pimple.
Friction and Hygiene
Clothing that rubs against your nipples during exercise is a surprisingly common trigger. Each stride or movement shifts the fabric slightly across your chest, and over the course of a workout, that friction can irritate hair follicles and pores enough to produce small bumps. Cotton shirts are particularly notorious for this, especially once they get heavy and wet with sweat. A snug-fitting moisture-wicking sports bra or shirt reduces that back-and-forth motion considerably.
Infrequent washing of bras, undershirts, or workout clothes also plays a role. Sweat, dead skin cells, and oil build up in the fabric and get pressed back against the skin, clogging pores. Switching to a clean bra daily and showering soon after exercise helps prevent breakouts in this area.
Hormonal Changes and Pregnancy
During pregnancy, sebaceous gland activity increases across the body. On the areola, this translates to visibly enlarged Montgomery glands that can look like a cluster of new pimples appearing almost overnight. This is a normal physiological change. The glands are ramping up oil production to prepare the nipple skin for breastfeeding, and they typically become more prominent in the first trimester and stay that way through lactation.
Puberty, hormonal contraceptives, and the luteal phase of the menstrual cycle (the two weeks before your period) can all trigger similar changes on a smaller scale. If bumps on your nipple seem to come and go in a monthly pattern, hormones are the most likely explanation.
Infections That Mimic Pimples
Folliculitis, an infection of the hair follicle, can occur on the chest and areola. It looks like a small red bump with a white or yellow center, often with some surrounding redness or warmth. It’s typically caused by staph bacteria. “Hot tub” folliculitis, caused by a different bacterium found in poorly maintained pools and hot tubs, can also produce clusters of bumps on the chest and breast area. Most mild cases clear up on their own with good hygiene and warm compresses.
A subareolar abscess is a deeper, more serious infection. Unlike a surface pimple, it produces a swollen, tender lump beneath the areola that may feel warm and can drain pus. You might also develop a fever, chills, or feel generally unwell. This type of infection needs medical treatment.
During breastfeeding, a yeast infection (thrush) can cause the nipple and areola to turn deep pink or red with peeling, flaky skin and tiny blisters. Milk blisters, or blebs, are another breastfeeding-specific bump. These are small, fluid-filled spots that form when milk gets trapped under the skin of the nipple, often from a poor latch or oversupply.
Signs a Bump Needs Medical Attention
Most nipple bumps are harmless and resolve within a week or two. But certain features set apart the ones worth showing a doctor:
- Persistent or worsening changes: A bump that doesn’t go away after two to three weeks, keeps growing, or keeps coming back in the same spot.
- Skin texture changes: Flaky, scaly, or crusted skin on or around the nipple that looks like eczema could be a sign of Paget’s disease of the breast, a rare condition that starts on the nipple surface and can spread to the areola.
- Nipple discharge: Any fluid coming from the nipple that isn’t breast milk, especially if it’s bloody or occurs without squeezing.
- Structural changes: Dimpling of the breast skin, a nipple that suddenly pulls inward, or a new lump in the breast or armpit.
- Signs of infection: Increasing redness, warmth, swelling, fever, or pus drainage that spreads rather than improves.
The CDC lists nipple changes, skin irritation, and unexplained discharge among the warning signs of breast cancer. These symptoms are far more common in benign conditions, but a bump that doesn’t behave like a normal pimple deserves evaluation.
Caring for a Nipple Pimple
If you’re dealing with a straightforward pimple or blocked gland, the best approach is to leave it alone. Squeezing or popping bumps on the nipple can introduce bacteria into already-delicate skin and lead to infection. A warm, damp washcloth held against the area for 10 to 15 minutes a few times a day can help open clogged pores or glands and encourage drainage naturally.
Avoid harsh acne products like benzoyl peroxide or salicylic acid on the nipple and areola. The skin there is thinner and more sensitive than your face, and these products can cause significant irritation. Gentle, fragrance-free cleansers are a better choice. If you’re breastfeeding, keep the area clean but avoid soap directly on the nipples, since it strips the protective oils your Montgomery glands are producing for a reason.