It is an unpleasant sensation that causes the desire to scratch and is a special sensation of the skin mucosa. The degree of severe itching varies, with some severe itching being tolerable and others being self-consciously severe. There are many causes of severe itchy skin, and patients need to go to the hospital as soon as possible so that it can be cured as soon as possible. Factors that cause itchy skin: 1. Fungal or bacterial infections This is the most frequent and most direct cause of itchy skin. 2.Allergic reaction Allergy due to food, medicine, insect poison or other substances, such as pollen allergy or contact with allergens, mostly occurs in allergic persons. 3. High concentration of bile acid When the concentration of bile acid in the blood increases, it will be deposited on the skin, leading to severe severe itching of the skin. Therefore, when the skin is itchy and yellow, you should go to the hospital to check the liver and gallbladder to see if you have gallstones. High calcium and phosphorus levels in the blood can also cause itchy skin. If the skin is dry and accompanied by frequent urination, urinary urgency, back pain, or even urine like water, or urine less, you should think about the possibility of kidney disease. Patients with chronic nephritis enter the uremic phase, due to the increase of urotoxins and protein derivatives in the blood, often causing generalized severe itching of the skin. 4, endocrine disorders such as hyperthyroidism patients, due to increased blood circulation in the skin, skin temperature increases, resulting in itchy skin, especially after sleep itching more intense. Diabetic patients, due to the increase in blood sugar, the body’s ability to defend against germs is reduced, susceptible to bacterial and fungal infections, which can also lead to severe itching of the skin.