Our skin often reveals more than we think, acting as an early sign of internal health problems. While many color or texture changes are harmless, some dark, thick, or velvety patches—known as acanthosis nigricans—can indicate metabolic issues or, in rare cases, cancers of the stomach, liver, or lymphatic system.

“Unusual darkening or thickening of the neck that doesn’t wash off or improve with exfoliation” may suggest hormone or protein level changes caused by internal illness.

In the armpits, darkness is often harmless, but if the skin becomes suddenly thick or velvety, it may signal a deeper issue. Similarly, dark or rough patches in the groin that appear or spread quickly should not be ignored, as they can go unnoticed for long periods.

Elbows and knees are usually darker due to friction, but sudden thickening or deep discoloration unresponsive to creams may require medical attention. Darkness around the lips or eyes that gradually worsens could also suggest internal imbalance.

If these changes come with fatigue or unexplained weight loss, seek medical advice immediately. As the article notes, “Early evaluation can be key to identifying and treating serious conditions.”