Hard knots on the neck are common in the following diseases: 1, sebaceous cysts, a disease caused by the obstruction of hair follicles, need to go to the hospital to check. If the disease is the need for surgical excision, in order to be able to get a radical cure. 2, lipoma, due to the abnormal distribution of fat. This disease is a benign swelling, do not worry too much. If the swelling is small, no special treatment is needed, and it can be observed regularly. Dietary structure can be improved, such as not eating food with too high fat content and increasing exercise appropriately. If the lipoma is large, it needs to be surgically removed under local anesthesia.3. Enlarged lymph nodes, lymph nodes are part of the body’s immune organs, due to bacterial or viral infections can lead to their enlargement, which can be helped by oral antibiotics, heat-clearing medications, etc. The enlargement of lymph nodes can be reduced. In short, it is best to go to the hospital in time to clarify the cause of the swelling in the neck.