Published on: 6/18/2025
What could cause my upper arm to swell unexpectedly?
Unexpected swelling in the upper arm can be caused by injury, infection, allergic reactions, blood clots, or lymphatic blockage.
Explanation
Upper arm swelling that appears suddenly may be due to:
Injury or trauma: Sprains, strains, or blunt force can cause swelling and bruising. Infections: Skin infections like cellulitis or abscesses can cause swelling, redness, and warmth. Allergic reactions: Bites, stings, or exposure to allergens may cause rapid swelling. Blood clots (deep vein thrombosis): Clots in the veins of the upper arm can block blood flow and cause swelling. Lymphedema: Blockage or damage to lymph vessels, often after surgery or radiation, can cause fluid buildup. Venous obstruction: Compression or blockage of veins may lead to swelling.
If swelling is sudden, painful, or associated with other symptoms like fever or difficulty moving the arm, seek medical attention 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.
- Manaqibwala MI, Ghobrial IE, & Curtis AS. (2014). Upper extremity thrombosis presenting as medial elbow .... Case reports in orthopedics, 24772360.
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