Another possible cause is cellulitis, a bacterial skin infection. It spreads quickly and can become severe without timely treatment. Antibiotics are usually necessary to stop the infection from worsening or spreading.

Superficial thrombophlebitis is another condition to consider. Here, a clot forms in a vein closer to the skin, leading to redness, tenderness, and pain. While often less dangerous than DVT, it can still be uncomfortable and may require treatment.

Chronic venous insufficiency may also cause swelling and redness. This condition develops when vein valves fail to circulate blood properly, leading to pooling, skin changes, or ulcers over time.

Other possible explanations include gout, arthritis, injury, or lymphedema. These conditions can cause pain and swelling but vary widely in severity and treatment needs.

It is especially important to seek urgent care if swelling appears suddenly, is painful, or comes with