How long can you have a dvt in calf before it causes a problem? is it true that it will not cause a pe if it's below the knee?

DVT: Calf DVT does not induce PE, however proximal extension will do from the distal femoral vein +- 30%. Complications from calf DVT, may occur at any time.

Deep Venous Thrombus: Calf DVT can cause problems immediately, to include pain, swelling, inflammation & can also extend or embolize. It is NOT true that a below knee DVT cannot embolize. Any leg DVT can embolize to the lungs (PE), since it has a direct path to the lungs through the deep system. Below knee DVT should usually be treated with blood thinner drugs to minimize risk of extension & embolization (PE).