Through physical examination, laboratory tests, and dermoscopy, you can determine the severity of hair loss. 1. Physical examination: Physical examination, such as visual examination. It can find out whether there is hair breakage, loss of luster, structural abnormalities, and also whether there is inflammation, scarring, atrophy, and flaking of the scalp. Hair pulling test examination means that a few hairs can be pulled out from any part of the scalp without any effort. 2. Laboratory tests: Laboratory tests include thyroid hormone measurement, free androgen, dehydroepiandrosterone and prolactin measurement, which can find out whether it is related to hair loss caused by thyroid and endocrine dysfunction diseases. 3. Dermoscopy: Dermoscopy can provide information about the opening of the follicular unit on the skin surface, the microstructure of the skin surface, the morphology of the hair shaft, the capillaries and the morphology of the hair root, which can help to determine whether the hair loss is serious. If you lose more than 100 hairs per day, it is recommended to go to the dermatology department of the hospital to find out the cause of hair loss.