Clinical hair testing usually refers to hair follicle testing, hair follicle examination can generally explore the density of the patient’s hair follicles, the degree of damage, metabolism and so on. 1. Hair follicle density: Hair follicle testing can usually be done through high power dermoscopy to explore the density of the patient’s hair follicles, so as to play an auxiliary role in the diagnosis of hair loss. 2. Hair follicle damage: Hair follicle testing can usually be done through high power dermoscopy to explore the degree of damage to the patient’s hair follicles, thus helping to understand the health of the patient’s hair, and to assist in determining the existence of folliculitis, follicular necrosis and other diseases. 3. Hair follicle metabolism: Hair follicle testing can usually be done through high-powered dermatoscopy to explore the metabolism of the patient’s hair follicles, which can help patients with abnormal oil secretion of the hair to determine the condition and cause of the disease. It is recommended that patients with abnormal hair conditions should consult a doctor in time, and after the follicle test, according to the test results, follow the guidance of a professional doctor to carry out the corresponding treatment.