How long can you have a blood clot before know so?

It can take several days or even weeks for symptoms of a blood clot to develop. In some cases, people may not experience any symptoms at all.

However, there are some general signs and symptoms that may indicate the presence of a blood clot, including:

* Swelling, pain, and tenderness in the affected area

* Changes in skin color or temperature

* Feeling of warmth or heat in the affected area

* Throbbing or cramping pain

* Difficulty breathing or chest pain

* Sudden loss of vision or speech

* Weakness or numbness on one side of the body

If you experience any of these symptoms, it's important to seek medical attention immediately, as early diagnosis and treatment of blood clots can help to prevent serious complications.