Published on: 6/18/2025
Why might one of my arms be swollen while the other is not?
One arm swelling while the other remains normal may result from localized issues like injury, infection, blood clots, or lymphatic blockage.
Explanation
Swelling in only one arm often points to a problem affecting that specific area, such as:
Injury: Sprains, fractures, or muscle strains can cause swelling in one arm. Infection: Localized infections like cellulitis cause swelling, redness, and warmth. Blood clots (deep vein thrombosis): A clot can block blood flow, leading to swelling and sometimes pain. Lymphedema: Blockage or damage to lymph nodes or vessels often causes swelling in just one arm, especially after surgery or radiation. Venous insufficiency or obstruction: Poor blood flow or vein blockage on one side can cause swelling. Allergic reactions: A bite or sting affecting one arm may cause localized swelling.
If swelling is sudden, painful, or accompanied by other symptoms like fever or chest pain, seek medical care promptly.
(References)
- Ciocon JO, & Galindo-Ciocon D. (1998). Arm edema, subclavian thrombosis, and pacemakers. Angiology, 9555935.
- Coates GR, Clements JB, Yium J, & Watlington J. (1988). Painful edema of the arm after insertion of single-needle .... Southern medical journal, 3347860.
- Geller BM, Vacek PM, O'Brien P, & Secker-Walker RH. (2003). Factors associated with arm swelling after breast cancer .... Journal of women's health (2002), 14670172.
Tell your friends about us.
We would love to help them too.
For First Time Users
What is Ubie’s Doctor’s Note?
We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.
Learn more about symptoms
Was this page helpful?
Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.