An eccrine poroma won't usually harm you, but it can make you uncomfortable -- especially if it forms on the sole of your foot. These noncancerous growths take hold in eccrine sweat glands, are slow to form and can take years to make themselves known. Even then, they typically only reach the size of a pencil eraser, but they can be hard to the touch and -- if exposed to friction -- exhibit a tendency to bleed. What's more, walking around on one can feel like having a pebble perpetually stuck in your shoe.
The treatment is simple: surgical removal. If left untreated, however, an eccrine poroma could give in to cancerous tendencies. Dying tissue and increased blood supply within the tumor creates a perfect storm for producing killer cells. Still, there's really no way to predict whether you'll develop an eccrine poroma; there's no genetic testing that may indicate a predilection for the disease. That's because the condition isn't hereditary [source: McCalmont].
From breaking into a nervous sweat in public situations to harboring a more serious condition, seemingly simple eccrine sweat glands represent millions of opportunities for health concerns. Fortunately for most people, these concerns never amount to more than a bit of perspiration.