Acanthosis nigricans is often connected to insulin resistance, excess weight, hormonal conditions, certain medications, or genetics. In many people, it can be associated with prediabetes or type 2 diabetes, although having these skin changes does not automatically mean someone has diabetes.
The skin changes themselves are usually harmless, but they can sometimes signal an underlying health issue. Treating the cause, such as improving blood sugar control or addressing a hormonal problem, may gradually help the patches become less noticeable.
A doctor should be consulted if the patches appear suddenly, spread quickly, become irritated, or occur with symptoms such as increased thirst, frequent urination, or unexplained weight changes. Most cases are not related to serious disease, but evaluation can help identify the cause early.
