Sure, it sometimes feels like there is always a new warning about everyday habits that seem harmless.
But after you see the potential downsides laid out clearly, you might decide that sleeping without underwear is a small change that can help you steer clear of some avoidable problems.
Even though many people prefer to stay covered at night for comfort, that choice could be getting in the way of your skin and body staying healthy.
Below are seven surprising reasons to ditch underwear at bedtime, plus why letting everything breathe could make a real difference to your overall comfort and well-being.
Increased risk of yeast infections & UTIs
There is nothing comfortable about dealing with a urinary tract infection or a yeast overgrowth.
These issues can be itchy and painful, and they tend to linger if not treated promptly.
So why might wearing underwear overnight raise the chances of running into one or both of these problems?
For women who sleep in underwear, that environment can raise the odds of a UTI or a yeast flare-up, which often requires topical treatments or antibiotics to clear.
And yes, even if you are thinking, “but these super-breathable cotton undies feel like I am wearing air,” the same concerns can still apply.
Skin irritation and even rashes
The team say: “Night-time is a time when your skin rests and repairs; however, underwear can disrupt this process.”
Lace, elastic, and synthetic blends can rub as you toss and turn, especially along seams and waistbands.
Combine that friction with natural sweat, and you have the perfect setup for chafing, redness, rashes, or even fungal issues.
People who manage eczema or sensitive skin may notice symptoms flare more when fabric stays pressed against the area all night.
It can reduce your sperm count
Testicles function best in a cooler, well-ventilated environment rather than one that traps heat.
Typically, scrotal temperature runs around 95˚F, which is about two degrees below core body temperature, and the scrotum shifts position to either retain warmth or release heat as needed.
When scrotal temperature climbs even a few degrees higher for long stretches, sperm production can be affected, which may impact fertility.
Another study had men wear insulated jockstraps for six to fourteen weeks and found that sperm counts decreased after just three weeks of use.
Snug underwear can contribute to that warmth, which is why cooler, looser sleepwear or going without can be helpful.
Lack of air circulation down below
Good airflow is an underrated part of staying comfortable and healthy overnight.
According to the experts: “Our skin regenerates at night, but it can only successfully do so with proper ventilation.”
“Underwear reduces airflow to these areas, keeping bacteria and sweat close to the skin.”
It can also increase odor and even cause acne-like bumps on the inner thighs or groin, especially in warmer weather.
Not so great sleep
Comfort matters when it comes to quality sleep, and small irritations can wake you up repeatedly.
Underwear can twist, bunch, or dig into the skin, which is distracting and can disrupt deeper sleep cycles.
Over time, poor sleep quality has been linked to fogginess, reduced focus, and a shorter fuse the next day.
Fungal infections
As mentioned earlier, skin irritation and trapped moisture can open the door to fungal growth.
Thrush and other fungal issues love damp, dark, and warm conditions, which tight sleepwear can create.
The risk rises if you head to bed in the same underwear you wore during the day, since it may already hold sweat and bacteria.
Hormone disruption
Many underwear fabrics are synthetic and may be treated with flame retardants, dyes, or finishing chemicals to boost stretch, color, or durability.
Prolonged contact with treated fabric can allow small amounts of these substances to transfer to skin, and some concerns center on potential effects on the endocrine system, which helps regulate hormones.
According to the underwear company: “The long-tern risks are still being studied; it’s recommended to avoid unnecessary exposure where possible, like during the six to nine hours of sleep.”
Doing so gives your skin a chance to breathe, lowers the risk of infection, and supports optimal temperature for male fertility.
If going fully nude is not your style, opt for loose, lightweight cotton pajamas so you stay covered while still allowing airflow where it counts.
