Sudden Redness and Swelling in One Leg: Causes and What to Know

1. Deep Vein Thrombosis (DVT)
A serious condition where a blood clot forms in a deep vein, often in the calf or thigh. Symptoms include swelling,

redness, warmth, and pain. Dangerous because clots can travel to the lungs, causing a pulmonary embolism. Risks:

immobility, surgery, pregnancy, smoking, obesity, and some medications. Sudden swelling with pain or shortness of breath needs urgent care.

2. Cellulitis (Skin Infection)
A bacterial infection causing redness, swelling, warmth, tenderness, and sometimes shiny skin. May include blisters,

fever, or fatigue. Usually starts from cuts, insect bites, or ulcers. Requires prompt antibiotics to prevent spread.

3. Superficial Thrombophlebitis
Inflammation and clotting in veins near the surface. Causes pain, redness, and warmth along a vein.