Bumps on the scalp can be caused by diseases such as folliculitis, nevus sebaceous, sebaceous cysts, and acne. 1. Folliculitis: Folliculitis is caused by bacterial infection of the hair follicle and its surrounding tissues, such as invasion of the hair follicle by Staphylococcus aureus, which leads to inflammation of the hair follicle. If it occurs in the scalp area, it leads to localized itchy or painful red papules and pustules. 2. Sebaceous nevus: this disease is considered to be developmental abnormality, which is usually formed by the wrong combination and arrangement of normal skin tissues. Most of the patients are born with symptoms that are not obvious due to the fact that the sebaceous glands are not yet fully developed; after puberty, the localized area may proliferate and thicken under the influence of hormones. 3. Sebaceous cysts: sebum secretion cannot be normally discharged from the follicle opening, and collects in the gland, forming cysts. If it occurs on the scalp, it may cause bumps on the scalp. 3. Acne: Acne, also known as pimples, is a common chronic inflammatory follicular sebaceous gland disease in dermatology, which mainly manifests itself as pimples, inflammatory papules, pustules, and in severe cases, nodules, cysts, and abscesses, which can also occur on the scalp, causing bumps on the scalp. The scalp long bumps, consider the skin problems, it is recommended to go to the hospital dermatology department, a clear diagnosis, and then give the appropriate drug treatment.