THE ANSWER
Scarring is not a normal outcome of electrolysis, but it is not impossible either. Temporary redness and small raised spots at treated follicles are normal and settle. Lasting marks are associated with over-treatment, poor technique, or picking at the area while it heals. No provider can honestly promise it will never happen.
Why
Electrolysis applies energy inside a follicle. Enough energy destroys the growth cells. Substantially too much, repeatedly, can affect the surrounding tissue, and that is where the risk of a lasting mark comes from.
This is why technique and settings matter, and why a patch test exists. A patch test shows how your own skin responds before a full session, which is more useful than any general statement about typical skin.
Two other factors matter more than people expect. The first is picking. Small spots that would settle on their own can leave marks if disturbed while healing. The second is skin type. Skin that tends toward post-inflammatory hyperpigmentation can darken after irritation, which is not scarring but does last, and it means treatment should be paced more gently.
Areas already damaged by years of plucking or ingrown hairs may also have existing marks. Those are pre-existing and hair removal does not treat them.
Will I get pitting or dark marks?
Pitting is associated with over-treatment and is not a normal outcome. Temporary dark marks can occur in skin prone to post-inflammatory pigmentation and usually fade, though this varies.
How should my skin react after a session?
Redness at the treated area, sometimes small raised spots at follicles, settling within hours to a day or two. That is the normal range.
What kind of unexpected reaction can happen?
Prolonged swelling, increasing pain rather than decreasing, heat, or anything that looks infected. None of these is typical, and all of them warrant contacting your practitioner and seeing a doctor if they worsen.
Will existing hyperpigmentation improve or get worse?
Marks from years of plucking or ingrown hairs sometimes fade once the cause is removed and the skin stops being irritated. That is not a treatment claim and it is not guaranteed. Existing pigmentation is a skin matter for a doctor or dermatologist.
What the evidence says
Temporary redness and small raised spots are the standard described reaction across the field. Lasting marks are associated with over-treatment and with disturbance during healing rather than with the method itself. Individual response varies enough that a patch test is the only reliable indicator for any given person.
What to do next
Ask for a patch test before a first full session, wherever you go. It is the single most informative thing you can do, and a provider who declines one is telling you something useful.
Ask what your practitioner expects your skin to do afterwards. See how to choose an electrologist and electrolysis aftercare.