Yam is not a hairy substance. Hairy material refers to food or substances that can trigger the occurrence of disease or cause recurrence or even aggravation of the original disease, mostly some highly nutritious or irritating food, such as seafood, beef and mutton, etc. Yam is a vegetable, does not belong to hairy material, forbidden to eat hairy material people without yam allergies and other conditions, generally can eat yam in moderation. Yam is warm in nature, sweet and light in taste, and has the effect of strengthening the spleen and stomach, nourishing the liver and kidneys, moistening the lungs and relieving cough, and can be used in Chinese medicine to treat spleen deficiency diarrhea, lumbar and knee weakness, insomnia, night sweats, diarrhea, loose stools and so on. From a western medical point of view, yam contains various digestive enzymes such as amylase, as well as mucin, vitamins, trace elements and other nutrients. Proper consumption of yam is beneficial to promote gastrointestinal motility, which is beneficial to people with digestive problems and gastrointestinal dysfunction. But not simply through the consumption of yam or a certain food to achieve the purpose of the treatment of disease, and some people are not suitable for eating yam. For example, people who are allergic to yam may experience skin erythema, itching, edema, nausea, vomiting and other symptoms after eating yam, and even cause anaphylaxis, unconsciousness, coma and other situations that require emergency medical treatment. In addition, the starch content of yam is relatively high and diabetic people need to control their intake, so it is not suitable for yam, and excessive consumption may cause blood sugar to rise. And people with bloating, stomach distension, dry stools and other conditions should also eat less or not eat yam to avoid aggravating the symptoms.