Published on: 6/18/2025
What could cause my arm to swell without any obvious reason?
Arm swelling without a clear cause may result from fluid buildup due to circulation or lymphatic problems, mild injury, infections, or medication side effects.
Explanation
If your arm swells without an obvious reason, possible causes include:
Lymphedema: Blockage or damage to lymph vessels can cause fluid buildup. Venous insufficiency: Poor blood flow may lead to fluid pooling in the arm. Unnoticed minor injury: Small strains or bumps might cause swelling even if you don’t remember trauma. Infections: Early infections like cellulitis may cause swelling before other symptoms appear. Medication side effects: Some medications can cause swelling as a side effect. Systemic conditions: Heart, kidney, or liver problems can cause fluid retention, sometimes affecting one limb more than the other.
If the swelling is persistent, worsening, or accompanied by redness, warmth, or pain, it’s important to seek medical evaluation.
(References)
- Ciocon JO, & Galindo-Ciocon D. (1998). Arm edema, subclavian thrombosis, and pacemakers. Angiology, 9555935.
- Manaqibwala MI, Ghobrial IE, & Curtis AS. (2014). Upper extremity thrombosis presenting as medial elbow .... Case reports in orthopedics, 24772360.
- Simonnet N, Marcantoni N, Simonnet L, Griffon C, Chakfe N, Wertheimer J, & Stephan D. (2004). [Puffy hand in long-term intravenous drug users]. Journal des maladies vasculaires, 15529083.
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