What could cause random swelling in my arm?

If arm swelling seems to appear randomly, some possible causes include:

Mild or unnoticed injury: Small strains or bumps can cause swelling even if you don’t remember a specific incident. Lymphedema: A condition where lymph fluid builds up due to blocked drainage, sometimes flaring up unpredictably. Venous insufficiency: Poor circulation may cause occasional fluid pooling in the arm. Infections: Early stages of skin infections like cellulitis can cause swelling before pain or redness develops. Allergic reactions: Exposure to allergens (like insect bites or certain materials) may trigger temporary swelling. Medication side effects: Some medications can cause fluid retention or swelling as a side effect. Systemic conditions: Heart, kidney, or liver issues can occasionally cause limb swelling that comes and goes.

If the swelling keeps returning, increases, or is accompanied by other symptoms, a medical evaluation can help identify the cause.