This kind of bump can be a swollen lymph node,a sebaceous cyst or a lipoma.Lymphadenopathy (swollen lymph nodes) is usually caused by a viral or bacterial infection along with other numerous causes.Treatment is usually cold compresses,over the counter anti-inflammatory analgesics(pain killers) like acetaminophen or ibuprofen,antibiotics if cause of infection is suspected to be a bacteria and surgical drainage if there is any abscess formation.
Sebaceous cyst is a closed sac or cyst below the surface of the skin and fills with a fatty white, semi-solid material called sebum produced by sebaceous glands of the epidermis.It is usually painless but can become painful if infected.Then antibiotics are needed.
Lipoma is a benign tumor.Usually it is painless and requires no specific treatment as it is self limiting.If it starts growing in size or becomes painful,then excision and drainage may be required.
All these are benign and self limiting conditions.But if the lump grows in size or becomes painful,then treatment may be required.
Hope it helps.Take care and pls do keep me posted if you have any additional queries.Kind regards.