Small white particles inside the hair may be dandruff, which can also be a symptom of a variety of diseases, such as seborrheic dermatitis, ringworm, head lice and so on. In some people with oily hair, the sebaceous glands in the head are prone to secrete oil and produce dandruff easily. The oil mixes with dandruff to form white particles, which can be relieved by regular cleaning of the head. Seborrheic dermatitis can cause the sebaceous glands in the head to secrete large amounts of oil, which can form sebum plugs in the hair follicles, which can form small white particles when adhering to the hair. Fungal infections causing tinea capitis, especially tinea alba, can be seen as grayish-white sets of scales at the roots of the diseased hair, which look like small white granules to the naked eye. Lice can cause head lice when they parasitize the scalp and can lay eggs on the proximal part of the hair, shaped like white granules. There may be other reasons for the presence of small white particles in the hair, and it is recommended that the patient go to the hospital in time to find out the cause and follow the doctor’s instructions for treatment.