I'm online now. type your question here large knot on side of calf but has the whole leg swollen from knee down

Swelling: If you have swelling from knee down on one side I would be very suspicious for a DVT. This should be checked.

Knot: It is possible you have a deep vein thrombosis. See a vascular surgeon for evaluation

How long: Any trauma to area, excessive exercise, or recent air travel? Symptoms could be a result from a blood clot to decreased blood flow from a large hematoma. Also spider bite. Please get examined if it persists or if you become short of breath, have fever, or further enlargement