What causes arm lump?

Arm lumps have many possible causes, including trauma, infections, inflammatory diseases, benign cysts and tumors, and cancers.

Traumatic causes of arm lumps

Minor and severe injuries, as well as internal trauma, can result in a localized swelling or lump on the arm including:

  • Broken bones
  • Hematoma (collection of blood in body tissues)
  • Sting or bite injuries

Infectious causes of arm lumps

An infection may produce one or more lumps in the form of a localized abscess or as a diffuse enlargement of lymph nodes in the arm. Infectious causes of lumps include:

  • Abscesses
  • Cellulitis (infection of the skin and tissue beneath the skin)
  • Papilloma virus infections (warts)

Inflammatory causes of arm lumps

Some conditions that lead to inflammation in the body may produce arm lumps including:

  • Gout (a type of arthritis caused by a buildup of uric acid in the joints)
  • Osteoarthritis (type of arthritis characterized by degeneration of the cartilage and bone in the joints)
  • Rheumatic fever (disease characterized by inflammation of the joints and of the connective tissue, especially in the blood vessels and heart)
  • Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)

Tumors that can cause arm lumps

Both benign and malignant tumors can cause arm lumps including:

  • Fibroma (benign tumor composed of fibrous or connective tissue)
  • Lipoma (benign fatty growth)
  • Lymphoma (cancer of the lymphatic system)
  • Melanoma (cancer arising in the melanocytes, or pigment-producing cells, in the skin or other parts of the body)
  • Nevi (moles of the skin)
  • Nonmelanoma skin cancers

Serious or life-threatening causes of arm lumps

In some cases, arm lumps may be a symptom of a serious or life-threatening condition that should be immediately evaluated by a health care provider. These include:

  • Abscess with spreading infection
  • Cancer
  • Fracture of bone
  • Joint dislocation

Questions for diagnosing the cause of a lump

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your arm lump including:

  • How long have you had the arm lump?
  • Are you experiencing any other symptoms along with the arm lump?
  • Is the lump getting bigger?
  • Is the lump painful?
  • Do you have lumps anywhere else on your body?

What are the potential complications of arm lump?

Arm lumps caused by cancer may have life-threatening consequences, depending on the type and stage (extent) of the cancer. Left untreated, lumps due to abscesses or serious infections may lead to widespread infection in the body. Following your treatment plan for serious causes of lumps can help reduce your risk of complications including:

  • Joint destruction and deformity
  • Necrosis of tissue or gangrene
  • Spread of cancer
  • Spread of infection
  • Ulceration or skin infection


  1. Skin rashes and other changes. FamilyDoctor.org. http://familydoctor.org/online/famdocen/home/tools/symptom/545.html.
  2. Soft tissue tumors - benign. Cedars-Sinai. http://www.cedars-sinai.edu/Patients/Health-Conditions/Soft-Tissue-Tumors---Benign.aspx.

What is arm lump?

An arm lump is a protuberance or localized area of swelling occurring on the arm. Other terms used to describe the various types of lumps include bump, nodule, contusion, tumor and cyst. Arm lumps can be caused by any number of conditions, including infections, inflammation, tumors or trauma. Depending on the cause, lumps may be single or multiple, soft or firm, painful or painless. They may gr... Read more about arm lumpintroduction


What other symptoms might occur with arm lump?

Arm lumps may accompany other symptoms, depending on the underlying disease, disorder or condition. Symptoms that cause arm lumps may also involve other body systems.

Related localized symptoms that may occur along with an arm lump

An arm lump may be accompanied by other localized symptoms including:

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Jul 29, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Infections and Contagious Diseases

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