The cause of blackened feet in foot soaks can be caused by staining on the feet or melanin deposits in the skin, or gangrene in diabetics. We can take targeted treatment for the different reasons for the blackening of the feet. Soak feet feet turn black is caused by long-term use of Chinese herbs, black vinegar soak feet, do not worry too much, generally stop using this material, switch to wash feet with water, feet can change back to the original color in a short time. Before using herbs, black vinegar and other materials to soak your feet, it is recommended to consult a professional doctor and soak your feet under the guidance of a doctor. If the water temperature is too high when washing the feet and burns the skin of the feet, it may cause skin pigmentation and blackening of the feet. Topical ointments can be used to restore the white state of the skin, or laser treatment can be used. In addition, if a diabetic patient’s feet turn black after soaking, he or she should be alert to the possibility of diabetic foot. In addition to the blackening of the feet, the patient may also have numbness and ulceration of the feet. First of all, we should apply hypoglycemic drugs to control blood sugar, and then carry out symptomatic treatment such as pain relief and anti-infection according to the condition of the feet, and in serious cases, surgery is needed. Daily foot soak should pay attention to choose the appropriate water temperature, at 37-42 ℃, to warm and comfortable, not too cool or too hot, and not too long.