Most scars do not sweat, or sweat significantly less than the surrounding skin. Sweat glands sit deep in the dermis, and when skin is damaged badly enough to scar, those glands are typically destroyed and replaced by dense, fibrous collagen that cannot produce sweat. The deeper the original injury, the more complete the loss.
Why Scars Lose the Ability to Sweat
Normal skin contains millions of tiny sweat glands coiled into the deeper layers of the dermis. When an injury penetrates past the surface layer of skin into those deeper layers, the healing process prioritizes closing the wound quickly. The body fills the gap with collagen fibers rather than rebuilding the complex structures that were there before. Sweat glands, hair follicles, and oil glands are all lost in this process.
Sweat glands are especially difficult for the body to replace because the specialized cells that form them are scattered throughout the dermis and cannot easily regroup. Even stem cells that could theoretically rebuild sweat glands are in short supply after significant skin damage, and current medicine has no reliable way to prompt the body to regrow them on its own.
It Depends on the Scar
Not every scar is completely dry. The type of scar, its depth, and the nature of the original injury all affect whether any sweating function survives.
Superficial scars from minor cuts or scrapes that only damaged the top layer of skin often retain most of their sweat glands, since the glands sit deeper than the injury reached. You may never notice a difference in sweating from these scars.
Deep surgical scars, severe lacerations, and third-degree burn scars tell a different story. These injuries destroy the full thickness of the dermis, wiping out sweat glands entirely. The replacement scar tissue has no mechanism to produce sweat.
Raised scars like hypertrophic and keloid scars fall somewhere in between. Research examining these scars under a microscope has found that sweat glands, hair follicles, and oil glands are reduced but not always completely absent. Some scattered glands can still be found throughout the dermis in these scars, which means a hypertrophic or keloid scar might produce a small amount of sweat, though noticeably less than normal skin.
What Else Scars Can’t Do
Sweating isn’t the only function that disappears. Scarred skin also loses its oil glands, which normally keep the skin moisturized and flexible. Without them, scars tend to feel dry, tight, and sometimes itchy, especially in warm or dry environments. Hair follicles are destroyed too, which is why scars are typically hairless.
This combination of missing structures is why scars look and feel so different from the surrounding skin. They lack the built-in moisture, temperature regulation, and texture that normal skin provides.
How This Affects Temperature Regulation
For a small scar on your hand or knee, the loss of sweating in that spot is functionally meaningless. Your body has plenty of surrounding skin to compensate. But when scars cover a large portion of the body, the impact on temperature regulation becomes serious.
Research on burn survivors has found a dramatic drop in heat tolerance when healed burn scars cover more than 40% of the body’s surface area. At that point, the body simply doesn’t have enough functioning sweat glands left to cool itself effectively. This can lead to heat-related problems including muscle cramps, dizziness, fatigue, flushed skin, and in severe cases, heat exhaustion or heat stroke.
People with extensive scarring often compensate by staying in cooler environments, wearing lightweight clothing, using cooling vests, and drinking extra fluids during physical activity or hot weather. The non-scarred portions of the body may actually sweat more heavily to try to make up for the areas that can’t, which some burn survivors notice as unusually heavy sweating from their intact skin.
Caring for Skin That Doesn’t Sweat
If you have a scar that doesn’t sweat, the main practical concern is keeping the skin hydrated from the outside. Without oil glands or sweat to naturally moisturize the area, scar tissue dries out faster and can become uncomfortable. Regular use of a fragrance-free moisturizer or emollient helps keep the scar pliable and reduces itching.
During exercise or hot weather, pay attention to how you feel. A small scar won’t cause problems, but if you have larger scarred areas, you may overheat faster than you expect. Cooling down early, taking breaks in the shade, and staying hydrated are straightforward ways to manage this.
Can Sweat Glands Be Restored?
Researchers are actively working on ways to regenerate sweat glands in scarred skin, primarily through stem cell therapy. Scientists have successfully reprogrammed certain stem cells into cells that resemble sweat gland tissue in laboratory settings. However, translating this into a treatment that works reliably in human skin remains a significant challenge. The number of available stem cells is limited, the efficiency of converting them into functional sweat gland cells is low, and the conditions inside scar tissue make it harder for new structures to take hold. For now, there is no clinically available treatment that can restore sweating to a scar.