What could it mean if your left arm is swollen?

If your left arm is swollen, some possible causes include:

Injury or trauma: A sprain, strain, or fracture can lead to localized swelling. Infection: Conditions like cellulitis can cause swelling, redness, and warmth. Blood clots (deep vein thrombosis): A clot in the veins of the arm can block blood flow and lead to sudden swelling. Lymphedema: A buildup of lymph fluid, often related to prior surgery or radiation, can cause one-sided arm swelling. Allergic reaction: A bite, sting, or exposure to an allergen may result in temporary swelling. Venous or lymphatic blockage: Obstruction in these systems may lead to fluid accumulation in the arm. Systemic conditions: Heart, liver, or kidney problems can also cause fluid buildup, although these usually affect both arms or legs.

If the swelling comes on suddenly, is painful, or is associated with other symptoms like redness, warmth, or shortness of breath, you can check your symptoms to help determine the next steps for your care.