Feeling small round balls under the collarbone of neck may be caused by localized lipoma, lymphadenitis, local boils, etc. The specific reasons are still to go to the hospital for examination to determine. 1. Localized lipoma: Lipoma is generally caused by abnormal lipid metabolism, inflammation stimulation, heredity and other factors, and it is mostly manifested in one or more lumps under the skin, and the tumor is soft and elastic, when the tumor is too big, the patient may also have pain and numbness. 2. Lymphadenitis: Lymphadenitis is mostly caused by cold, upper respiratory tract infection and other reasons, the patient’s lymph nodes will be enlarged and painful, mostly located in the neck or armpits, the condition is more serious, the patient will also have abscesses, fever and other symptoms. 3. Localized boils: boils are usually caused by poor living environment, long-term alcohol consumption, etc. Patients’ skin lesions are often manifested as slightly elevated red painful nodules, mostly pea-sized, which are commonly found on the face, buttocks, and neck, and when the condition is serious, patients will also have headache, fever and other systemic symptoms. If the neck below the clavicle feel small round ball situation, should promptly go to the hospital for medical treatment, follow the doctor’s instructions for treatment.