RN
There is a number worth knowing before you pick anything up, and it is not the one usually quoted in articles like this.
A 2017 survey published in JAMA Dermatology asked more than seven and a half thousand people about grooming below the waist. About three quarters had done it. Of those, just over a quarter had injured themselves. Lacerations accounted for around six in ten of those injuries. For men, the single most common site was the scrotum, at roughly two thirds of male injuries.
Roughly one and a half percent of the injuries were serious enough to need medical attention. Small share, large denominator.
None of this is an argument against grooming. It is an argument for treating it as a task with a technique rather than a chore you rush through while the water runs, which is how most of that quarter got there.
The hygiene claim, addressed properly
The standard justification for all of this is hygiene, and it is the weakest part of the case.
Body hair in that region is not a sanitation problem. It does not incubate anything that washing does not handle, and there is no clinical basis for the idea that removing it makes you cleaner. What removing it demonstrably does is create small breaks in the skin — which is why the research interest in this topic has clustered around injury and around observed associations between grooming and skin infections, rather than around benefits.
Those infection associations are correlational and heavily tangled with how sexually active a person is, so nobody should be frightened by them either. The honest summary is narrower than both camps want: grooming is an aesthetic preference, held by a lot of people, that carries a small and manageable injury risk and confers no hygiene benefit.
Which is a perfectly good reason to do it. Preferences do not need a medical justification, and it is worth noticing how much of the writing on this subject invents one anyway.
Trimming, which is most of what people actually want
Nearly everyone asking about this wants shorter, not gone. Trimming carries almost none of the risk that shaving does, because a guard never touches skin.
Use a guard, always. The temptation to remove it for a closer finish is where the scrotal lacerations come from. Skin there is mobile and loose and will feed itself into an unguarded blade before you have registered what happened.
Trim dry, shave wet. This is counterintuitive and it is the reverse of the advice usually given. Dry hair stands away from the skin and cuts cleanly; wet hair lies flat, clogs the blade and drags. Save the water for shaving.
Go against the growth direction with the trimmer, holding the skin taut with your free hand as you go. Tension is the whole technique. Loose skin is what gets caught.
Work from a longer guard down. You can always take more off. Nobody has ever successfully put it back.
Shaving, if you are going that far
This is where the injury statistics come from, so the discipline matters more.
The American Academy of Dermatology's actual shaving guidance is short and boring and mostly ignored:
- Wash first with warm water, and shave at the end of a warm shower rather than the start. Warm water softens hair so it cuts instead of snapping, and that snapping is a major contributor to ingrown hairs.
- Shave with the grain, not against it. Against-the-grain gets you closer and gets you razor bumps.
- Use a sharp blade and replace it roughly every five to seven uses. A dull blade is the single biggest predictor of irritation, because it drags rather than cuts.
- Long strokes, no stretching the skin excessively, no pressure. Let the blade do it.
You will also see a claim floating around that washing before shaving cuts irritation and ingrowns by sixty percent, attributed to the AAD. That figure does not appear in their guidance and there is no visible source for it. Wash first anyway — the advice is real even where the statistic is not.
Trim before you shave, always. Running a razor through full-length hair is how blades clog and how skin gets pulled.
Aftercare, briefly
The first day or two afterwards is when regrowth causes most of the trouble.
Skip anything with alcohol or fragrance on freshly shaved skin, for reasons that will be obvious within about four seconds if you ignore this. Loose cotton rather than anything tight while regrowth starts. And leave ingrown hairs alone — digging one out converts a bump that would have resolved on its own into a small infection that will not.
If something looks infected, spreads, or is still getting worse after a couple of days, that is a doctor's call rather than a forum's. Same for any recurring problem in the area, which can have causes that have nothing to do with grooming at all.
On the part nobody needs to be told
The framing that started this whole genre of article — that not doing it is a failure of consideration toward someone else — deserves less airtime than it gets.
Preferences here vary enormously, in every direction, and the ones people actually hold bear very little resemblance to what appears on screen. A partner who cares will tell you if you ask. That single conversation outperforms every technique above, and it is the one piece of advice on this page that costs nothing and carries no risk of lacerating anything.