Obesity neck black may be physiological phenomenon, may also be acanthosis nigricans, etiology is unknown, and genetic, obesity, endocrine disorders, obesity will cause excessive local folds, local friction, pigmentation. Obesity neck black may be a normal physiological phenomenon, mainly related to dietary factors, sun exposure and other environmental factors and genetic factors. Pay attention to adjust the diet structure, appropriate exercise, avoid sun exposure, the symptoms will improve. Obese neck black may also be acanthosis nigricans, such as diabetes, adrenal disease and other endocrine diseases can cause acanthosis nigricans. Obese patients due to the body’s obesity will cause excessive local folds, which leads to increased sweating and metabolites, easy to cause localized hyperpigmentation, causing the symptoms of neck black. If there is any discomfort, consult a doctor in time to avoid delaying the condition.