DefinitionHump behind the shoulders is a lump of fat on the back of the neck.Alternative NamesBuffalo hump; Dorsocervical fat padConsiderationsA hump behind the shoulders by itself is not a sign of any one, specific condition. The doctor must consider this along with other symptoms and test results.Common CausesCertain drugs used to treat AIDSExtended use of certain steroid medicines, including prednisone, cortisone, and hydrocortisoneExtreme obesityHypercortisolism (caused by Cushing syndrome)Osteoporosis may cause a curvature of the spine in the neck called kyphoscoliosis. This causes an abnormal shape but does not by itself cause excessive fat in the back of the neck.Home CareIf the hump is caused by a certain medicine, your doctor may tell you to stop taking the drug or change your dos