I bruised my mid thigh by bumping rather hardly into a desk.  After the third day, bruising formed, and now on the 5th day I woke up with a red area about as big as a 50 cent piece over a lump. It hurts quite  badly when touched. Should I be concerned of a blood clot? Also as a note, I have had both knees replaced 3 years ago.
Hi. Welcome to Chat Doctor . I have gone through your query and can understand your concerns. As per your complaint it seems that due to bumping the thigh with the desk there has been traumatic injury to the soft tissues leading to swelling and the red area seems to be due to broken blood vessels leading to spillage of blood in the soft tissues and hematoma formation. You need not worry as gradually as the healing will proceed and inflammation will subside pain will reduce. Blood will also gradually disintegrate from the soft tissues leading to fading of redness. I would suggest you to take anti-inflammatory painkiller like Ibuprofen. Do cool compresses over the swelling. You can apply an analgesic ointment over it. You can also apply Heparin ointment as it will help in fading of the bruising and faster disintegration of the blood clot. Elevate your leg while lying down. In case if the condition worsen or there is no improvement in a week consult a General Physician and get evaluated. Hope this information helps. Thanks and regards. Chat Doctor.