Ingrown hairs are aggravating, sometimes painful, and can leave lasting marks on skin if repeatedly picked at or infected. They occur most commonly in areas of frequent shaving or waxing, the bikini line, legs, underarms, and face for men, and they’re more common in some people than others. Understanding the mechanism helps distinguish the interventions that actually reduce them from the ones that just treat them after the fact.
What causes ingrown hairs
An ingrown hair forms when a hair growing from a follicle curves back into the skin rather than growing upward and out. This happens through two main mechanisms:
The hair exits the follicle but curves back into the skin surface, either because the sharpened tip (from a razor cut) is more likely to penetrate the adjacent skin, or because the hair is curly and curves naturally.
The hair doesn’t exit the follicle at all, growing sideways under a layer of dead cells or trapped skin. This is called a “pimple-under-the-skin” type ingrown that doesn’t break the surface.
Both produce inflammation: the hair is a foreign body from the skin’s immune perspective once it’s growing in the wrong direction, and the follicle mounts an inflammatory response that creates the red, tender bump characteristic of ingrown hairs.
Who gets them most
People with tightly coiled or curly hair are significantly more susceptible to ingrown hairs because the natural curl of the hair shaft means it’s more likely to curve back toward the skin after cutting. This is why ingrown hairs (pseudofolliculitis barbae) are particularly common in Black men who shave, with some estimates suggesting up to 80% experience the condition.
Dead skin cell buildup over follicle openings is the other primary risk factor, making people with slower skin cell turnover, those who don’t exfoliate, or those with very dry skin more susceptible regardless of hair texture.
Shaving technique matters. Shaving against the grain gives a closer shave but cuts the hair at a sharper angle and below the skin surface level, making re-entry more likely. Tight clothing immediately after shaving creates friction that can push freshly cut hairs back into the follicle.
Prevention: what works
Exfoliation is the most impactful preventive measure. Removing dead skin cells that trap hairs beneath the surface gives growing hairs a clearer exit route. Regular use of a body scrub on shaved areas, two to three times per week, consistently reduces ingrown hair frequency in most people. Physical exfoliation directly clears the follicle openings. Chemical exfoliation with salicylic acid (BHA) works particularly well because its oil-solubility means it penetrates into follicles where the trapping occurs.
Shaving technique improvements: use a single-blade razor or electric razor rather than multi-blade razors, which cut below the skin surface. Shave with the grain rather than against it. Shave on warm, softened skin with adequate lubrication from a quality shaving cream or gel. Rinse with cold water after shaving to close follicle openings before the hair has a chance to grow sideways.
Moisturise after shaving. Dry skin over follicle openings is more likely to trap hairs than well-hydrated skin. A lightweight, non-comedogenic moisturiser applied to shaved areas after shaving supports barrier recovery and keeps the skin surface from thickening over follicle openings.
Loose clothing after shaving: tight synthetic fabrics create friction and heat that pushes short hair stubs back into follicles immediately after cutting. Cotton or loose-fitting garments after shaving reduces this factor.
When they occur: how to handle them
A genuine ingrown hair, one where you can see the hair trapped beneath the skin surface, can be carefully freed with a sterile needle or fine-tipped tweezers. Sterilise the instrument with alcohol, pierce the loop of skin trapping the hair, and gently guide the tip out. Don’t dig, don’t squeeze, and don’t attempt to pull the entire hair out of the follicle this way. Removing only the trapped portion and letting the hair grow out naturally prevents the cycle from repeating.
If the bump is red, swollen, and clearly inflamed without a visible hair, it’s either a very deep ingrown or an infected follicle. Applying a warm compress several times daily helps the hair work its way to the surface. An antibiotic cream is appropriate for infected follicles. A dermatologist is worth visiting if a persistent bump doesn’t resolve within a few weeks.
Picking at ingrown hairs creates more inflammation, spreads bacteria, and dramatically increases the chance of post-inflammatory hyperpigmentation (dark marks that remain after the ingrown resolves). This is particularly significant in deeper skin tones where PIH is more common and darker. Resist picking.
Long-term reduction strategies
Laser hair removal is the most effective long-term solution for recurrent ingrown hairs in areas where permanent hair reduction is acceptable. The laser targets the hair follicle, reducing hair production over multiple sessions. Without hair, there are no ingrown hairs. This is particularly relevant for pseudofolliculitis barbae in men and for bikini line or underarm ingrowns.
Switching hair removal methods: waxing removes hair at the root rather than cutting it, which eliminates the sharpened-tip mechanism. However, waxing can cause ingrowns through the other mechanism (hair growing from the follicle in the wrong direction post-wax). Many people find one method produces fewer ingrowns than the other depending on their hair texture.
Chemical depilatories dissolve hair at the surface rather than cutting it, eliminating the sharpened-tip problem. They’re appropriate for people with significant ingrown hair issues who find razor cutting the primary cause, though they have their own sensitivity concerns for some skin types.
The combination of regular exfoliation (both physical and chemical), careful shaving technique, and consistent moisturisation reduces ingrown hair frequency substantially for most people without requiring a change in hair removal method.