The weather is cold and the mouth is black.

Are your hands and feet cold? Generally speaking, this is caused by poor peripheral circulation. Usually, you can soak your feet with hot water, take a hot bath often, exercise and strengthen the heat operation in your body (just sweat slightly).

In dietotherapy, you can eat some warm and spicy food, which can promote blood circulation.

And wear warm clothes to keep warm, and don't be too hungry.

In addition, if your lips are usually purple, you may have insufficient blood supply to your heart. It's best to go to the hospital for a routine electrocardiogram.