Your skin temporarily lightens or turns white when pressure is applied. This momentary color change is a normal physiological response, a natural function of the body’s circulatory system, and generally not a cause for concern.
Understanding Why Your Skin Changes Color
The temporary whitening of skin under pressure is scientifically termed “blanching.” This occurs because the pressure momentarily forces blood out of the tiny blood vessels located close to the skin’s surface, known as capillaries. These capillaries are microscopic vessels that form a vast network just beneath the epidermis, the outermost layer of your skin.
Compression triggers vasoconstriction, the narrowing of these blood vessels. As the capillaries constrict, blood is temporarily pushed away from the area under pressure, causing the skin to appear white or pale. The white color you observe is not the skin’s pigment changing, but the temporary absence of red blood, revealing underlying connective tissues.
Once the pressure is released, the capillaries relax, and blood flow rapidly returns to the affected area. This swift return of blood restores the skin’s normal color within seconds. Sometimes, a temporary redness, known as reactive hyperemia, might be observed as blood rushes back into the previously constricted vessels. This entire sequence of events—from blanching to rapid return of color—is a healthy indication of proper blood circulation.
When to Be Concerned About Skin Discoloration
While temporary blanching is a normal response, prolonged or unusual skin discoloration can sometimes signal an underlying health issue. If the skin remains white or pale for an extended period after pressure is removed, or if it takes more than a few seconds for the color to return, it could indicate sluggish blood circulation. This delayed return of color, sometimes referred to as poor capillary refill, might be a sign of issues like dehydration or even shock in more severe cases.
Certain medical conditions can also cause abnormal blanching or discoloration. For instance, Raynaud’s phenomenon involves episodic constriction of blood vessels, often in the fingers and toes, leading to blanching, numbness, and pain, especially in response to cold temperatures or stress. Other conditions that might involve prolonged blanching include frostbite, where tissues freeze and blood flow is lost, or the early stages of pressure sores, which indicate impaired blood flow to the skin.
It is advisable to consult a healthcare provider if blanching is accompanied by other concerning symptoms, such as persistent pain, numbness, coolness of the skin, or a bluish or purplish discoloration. Additionally, if the skin does not return to its normal color quickly, if blanching occurs without applied pressure, or if there are changes in skin texture or signs of skin breakdown, medical evaluation is warranted.