The darkening of the skin caused by underwear strangulation is due to improper underwear, excessive skin friction caused by hyperpigmentation, which can be removed by choosing the right underwear with medication. 1. Choose the right underwear: Use a measuring tape to measure the circumference of the upper and lower busts, and choose the right size of underwear according to your own size, or you can choose with the help of the salesperson. When purchasing, try to choose more comfortable underwear with less patterned decorations to minimize the friction on the skin. 2. Medication: Apply sodium heparin compound gel, hydroquinone cream or mucopolysaccharide polysulfate cream to the area where the strangulation marks have appeared and the skin is blackened, and use it 2 to 3 times a day to accelerate the skin metabolism for the purpose of removing the marks. The blackening caused by underwear strangulation is generally not a major effect, if accompanied by other physical discomfort, it is recommended to go to the regular hospital for examination to clarify the cause of the disease before treatment.