Stretch marks under the armpits from working out

These lines are also called striae. They may first look pink, red, purple, or darker than nearby skin, then gradually become lighter and less noticeable. The armpit area can be affected when the chest, shoulder, or upper-arm muscles change size, or when weight changes alter tension across the fold. Stretch marks are a skin change, not proof that a workout caused damage.

New marks may itch or feel slightly tight. Scratching, deodorant irritation, and friction from close-fitting sports clothing can make the area more uncomfortable, but they do not create the underlying stretch mark by themselves.

Keep the fold gently clean and moisturised, pat it dry after exercise, and choose breathable clothing that reduces rubbing. Increase training and muscle load gradually, and avoid applying irritating exfoliants to freshly inflamed skin. Creams and oils may ease dryness but generally do not erase established marks.

If appearance bothers you, a dermatologist can assess the colour, age, and texture of the marks. Options may include Microneedling, Fractional Laser Treatment, RF Microneedling, or Carboxytherapy. Suitability depends on skin tone, whether the marks are new, and the risk of pigment changes or irritation.

Arrange a medical assessment if the marks appear suddenly alongside easy bruising, marked weakness, facial rounding, or prolonged use of steroid medicines. Seek care sooner for pain, warmth, swelling, discharge, or a rash in the fold, since those features suggest a separate skin problem rather than uncomplicated stretch marks.

Ask whether the lines fit stretch marks, which treatment is appropriate for your skin tone, how many appointments may be needed, and how to protect the armpit from irritation while it heals.