Ingrown hairs in the underarms: causes, prevention and solutions

Why do we have underarm hair at all?

Underarm hair is neither an accident nor useless — it is part of the body’s natural protective mechanism. It helps regulate temperature, protects sensitive skin from friction and irritation, and helps carry sweat away.

That does not change the fact that most people remove it for aesthetic or hygienic reasons. And it is exactly the way they do it that decides whether they get smooth skin or a fight with ingrown hairs.

Why does underarm hair grow inwards?

Ingrowth happens when a hair fails to get out of the follicle above the surface of the skin and curls back underneath it. The skin reacts with irritation and inflammation as it tries to expel the foreign body — hence the painful spots and lumps in the underarm. The underarm is more prone to this than other zones because thin skin, friction and daily shaving all meet here.

The four main causes of ingrown underarm hair:

Cause	How it leads to ingrowth
Poor removal technique	Shaving against the direction of growth bends the hair and points it into the skin; a blunt or dirty razor irritates the skin and can trigger inflammation.
Genetics and hormonal changes	Hair density is inherited. Hormonal swings during the menstrual cycle or pregnancy intensify underarm hair growth.
Excess weight and an unsuitable diet	Folded skin in the underarm increases friction; a diet rich in fats and sugars affects hormone levels unfavourably.
Friction and skin irritation	Tight clothing, synthetic materials and deodorants or antiperspirants with aggressive chemicals.

What are the symptoms of ingrown underarm hair?

An ingrown hair announces itself first with itching and redness; pain comes only afterwards. The typical progression is: irritation → tenderness to the touch → a hard, painful lump caused by inflammation deeper down.

What to watch for:

• Itching in the underarm area — the most common first symptom.
• Irritation and redness of the skin, which is sensitive and painful to the touch.
• Hard, painful lumps caused by inflammation in the follicle.
• Darker, more visible hair under the surface of the skin.
• Increased sweating — hair blocks the outlets of sebaceous and sweat glands and sweat accumulates in the underarm.

If the painful inflammation keeps returning or does not heal, do not rely on self-treatment and consult a dermatologist. Besides the acute inflammation they can also identify the cause behind it.

Which hair removal methods make ingrowth worse?

Most common methods remove only the visible part of the hair, or pull it out with the root without preventing it from growing back — and it is the regrowing hair that can curl under the skin. The exception is the laser, which reaches the follicle for good.

Method	Durability	Effect on ingrowth
Razor	A few days	High risk — the blade needs replacing after almost every use, plus a quality gel or foam
Epilator	Several weeks	Medium — hair grows back more slowly, but irritation is a risk and an unclean device can cause infection
Wax	4 to 6 weeks	Medium to high — painful, irritates the skin, and a broken hair grows in the wrong direction
Sugar paste	4 to 6 weeks	Medium — the follicle is not destroyed, the hair returns
Depilatory cream	A few days	Medium — the chemical components can irritate and dry out the skin
Laser hair removal	Long term	Minimises the risk — the hair goes together with the root

A chapter of its own is razor rash. If it appears regularly, the culprit is usually a blunt or poor-quality razor, or an allergy to the cosmetic product used. The same mechanism works in other zones — we describe it in the article about hair on the belly.

How does laser hair removal of the underarms solve ingrowth?

The laser beam reaches the hair right at the root and prevents it from growing further. That removes the very cause of ingrowth — the regrowing hair that can curl under the skin. At the same time the treatment does not create the tiny open wounds that plucking does, so the skin stays calm.

Why the underarm is a rewarding zone for a laser:

• It is a small area, so a session takes only a few minutes.
• The treatment is gentle — the device cools the skin at the same time as the laser pulse.
• The result is long term, so daily shaving and its consequences fall away.
• Both women and men come for it; it is one of the most popular treatments of all.

At Laser Clinic we choose between the diode LightSheer DUET for darker and tanned skin and stronger hair and the alexandrite Deka Motus AX Moveo for light skin and fine hair. Which device suits your skin better is determined at the free consultation — we describe the differences on the page about our lasers.

How many sessions and what does underarm epilation cost?

The exact number of sessions depends on how much of the hair is in its active growth phase at the time of treatment, so it differs for every client. The prices below are per session; we confirm the exact amount according to the extent at the free consultation.

Item	Value
Underarms	1 000 CZK per session
Forearms	1 500 CZK per session
Indicative number of sessions	5 to 8, depending on hair density
Maintenance treatment	usually once a year

Meanwhile the cost of razors, gels and shaving foams adds up for a lifetime — from that perspective, a one-off investment in a laser pays for itself. A complete overview of zones is in the body hair removal price list, and for men in the offer for men.

How do you care for the underarms so hair does not grow inwards?

The basis of prevention is clean, hydrated and unirritated skin. It is not a one-off intervention but a routine — and a matter of what to avoid.

• Exfoliate 1 to 2 times a week. A scrub removes dead cells that clog the follicles. Overdone exfoliation, however, damages the skin.
• Moisturise. After showering apply a cream for sensitive skin, without fragrance and alcohol.
• Wear natural fabrics. Cotton limits friction; tight synthetic clothing increases it.
• Choose a gentle antiperspirant. Aggressive chemicals irritate the sensitive underarm skin.
• Wash the underarms with a mild soap and rinse thoroughly so no residue remains.
• Do not rush when shaving. Warm water, a sharp blade and the direction of growth are the three conditions that together reduce the risk the most.

Ingrown underarm hair is not only a cosmetic problem — itching, inflammation and increased sweating can spoil a whole day. If it keeps coming back despite all the prevention, come and discuss it with us: in Prague you will find us at three branches (Vinohrady, Karlovo náměstí, Vysočany), open every day from 9:00 to 21:00, and the consultation is free.