Ingrown hairs happen when a hair curls back into the skin or gets trapped beneath it instead of growing outward. If you’re suddenly dealing with more of them than usual, something has likely changed: your grooming routine, your clothing, your skin’s ability to shed dead cells, or even your hormones. The good news is that most causes are identifiable and fixable.
How Ingrown Hairs Actually Form
There are two ways a hair becomes ingrown. In the first, the hair never makes it out of the follicle at all. It hits a blockage, usually a plug of dead skin, and curls sideways beneath the surface. In the second, the hair exits the skin normally but then curves back down and re-enters it. Either way, your body treats the embedded hair tip like a foreign object and mounts an inflammatory response, producing the red, swollen, sometimes painful bumps you’re seeing.
Understanding which pathway is causing your ingrown hairs matters because the solutions are different. Blocked follicles point to a skin care issue. Hairs that exit and curve back in point to hair texture, grooming technique, or both.
Your Hair Type Is the Biggest Risk Factor
Tightly curled hair is the single strongest predictor of ingrown hairs. A curved hair follicle produces hair that naturally spirals as it grows. When that hair is cut short, the sharpened tip follows its curl right back toward the skin surface, where it can pierce and re-enter. This is why ingrown hairs disproportionately affect people with coarse, curly hair and why certain body areas (the beard, bikini line, and underarms) are more prone than others.
If your hair type hasn’t changed but your ingrown hairs have increased, the cause is likely something else on this list. But if you’ve recently started shaving or waxing an area where your hair grows in tight curls, your hair texture is probably the primary driver.
Multi-Blade Razors Make It Worse
The way multi-blade cartridge razors work is a major contributor. The first blade lifts the hair up and partially cuts it. Before the hair can retract, the second (or third, or fifth) blade catches it and cuts it even shorter. The result is a hair that ends up trimmed below the skin’s surface. For straight hair, this just means a closer shave. For curly hair, it means the sharpened stub starts growing at an angle beneath the skin and never breaks through.
Shaving against the grain compounds the problem. It produces an even closer cut, but it also distorts the angle at which the hair sits in the follicle, making re-entry more likely. Dull blades are another culprit: they tug and tear rather than cutting cleanly, leaving ragged hair tips that snag on surrounding tissue.
If your ingrown hairs coincide with a new razor, a lazier blade-changing schedule, or a shift to shaving more frequently, your grooming routine is the likely cause. Switching to a single-blade razor, shaving with the grain instead of against it, and replacing blades regularly can reduce ingrown hairs significantly.
Dead Skin Buildup Traps Hair Underneath
Your skin constantly sheds dead cells from its surface. When that process slows down or goes wrong, a layer of dead skin can seal over the opening of a hair follicle, trapping the growing hair beneath it. This is the same mechanism behind keratosis pilaris, those small rough bumps many people get on their upper arms and thighs. In that condition, a protein called keratin fills the follicle opening instead of shedding normally, plugging it shut.
Several things can slow your skin’s natural exfoliation: dry weather, dehydration, skipping moisturizer, or simply not exfoliating areas you shave. If you’re noticing more ingrown hairs during winter or after a change in your skin care routine, buildup is a strong suspect. Gentle exfoliation two to three times a week (a washcloth, a mild scrub, or a chemical exfoliant with salicylic acid) keeps follicle openings clear so hair can grow out freely.
Tight Clothing and Friction
Anything that presses against your skin repeatedly can damage hair follicles and push growing hairs sideways. Tight jeans, compression leggings, underwear with narrow elastic edges, and even backpack straps are common offenders. Fabrics that trap heat and sweat make the problem worse because moisture softens the skin, making it easier for a sharp hair tip to pierce back in.
The areas most affected by friction-related ingrown hairs are predictable: the bikini line (underwear elastic), the inner thighs (tight pants), the back of the neck (collars and helmet straps), and the buttocks (prolonged sitting in non-breathable fabric). If your ingrown hairs cluster in one of these zones, switching to looser, moisture-wicking clothing can make a noticeable difference. Freshly shaved skin is especially vulnerable, so avoid tight clothes for a day or two after grooming.
Hormonal Changes Can Increase Hair Growth
Hormones called androgens control how thick and coarse your body hair grows. When androgen levels rise, hair follicles can shift from producing fine, thin hair to growing thick, dark, coarse strands. This thicker hair is more likely to become ingrown, especially in areas where you remove it regularly.
In women, elevated androgens can cause a pattern of excess hair growth called hirsutism, with new coarse hair appearing on the face, chest, and abdomen. Conditions like polycystic ovary syndrome (PCOS), certain medications, and natural hormonal shifts during puberty, pregnancy, or menopause can all raise androgen levels. If you’re noticing both more hair and more ingrown hairs in new areas, a hormonal shift may be the underlying reason.
Waxing and Plucking Carry Their Own Risks
Switching from shaving to waxing or tweezing doesn’t necessarily solve the problem. Both methods pull the entire hair out from the root, which means the new hair has to find its way back through the follicle and out of the skin from scratch. If the follicle opening has closed over or the new hair grows at a slightly different angle, it can get trapped. Waxing also causes skin irritation and minor swelling that can temporarily narrow follicle openings, making ingrown hairs more likely in the days after a session.
If waxing is your primary removal method, exfoliating the area gently starting about two days after your appointment helps keep follicles open as new hairs begin to emerge.
When an Ingrown Hair Gets Infected
Most ingrown hairs are annoying but harmless. They resolve on their own once the hair breaks through or is gently freed. But an ingrown hair creates a small wound beneath the skin, and bacteria can enter that wound, especially if you pick at it or shave over it.
A mild infection looks like a red, irritated bump with a visible white or yellow center of pus. This is folliculitis, and it often clears up with warm compresses and by leaving the area alone. A deeper infection can develop into a boil: a warm, painful lump filled with pus that may leak whitish or bloody fluid. In rare cases, multiple connected boils form a carbuncle, which can cause fever and fatigue along with significant pain.
The progression from ingrown hair to boil to carbuncle is uncommon, but it’s worth recognizing the signs. A bump that’s growing larger, increasingly painful, warm to the touch, or leaking fluid has moved beyond a simple ingrown hair.
A Practical Checklist for Reducing Ingrown Hairs
- Switch your razor. A single-blade razor cuts at the skin surface instead of below it. If you stay with a multi-blade, at least shave with the grain and change cartridges frequently.
- Exfoliate regularly. Two to three times per week in areas prone to ingrown hairs. A gentle scrub or a cleanser with salicylic acid keeps dead skin from plugging follicles.
- Moisturize after shaving. Hydrated skin is more flexible, which makes it harder for a hair tip to pierce back in.
- Loosen up. Avoid tight clothing over freshly shaved areas for at least 24 hours. Choose breathable fabrics when possible.
- Don’t dig. Picking at ingrown hairs with tweezers or fingernails introduces bacteria and increases scarring. A warm compress for 10 to 15 minutes can help the hair surface on its own.
- Consider longer hair. If a particular area gives you persistent trouble, letting the hair grow slightly longer (even a few millimeters) keeps the tip from curving back into the skin.