Does negative d-dimer 100% rule out dvt?

No. No test is l00% positive for DVT but an negative d-dimer together with a negative lower extremity venous ultrasound is very strong evidence for no DVT from the femoral vein down.

Related Questions

Does a negative d dimer rule out a DVT and PE? Been having chest and calf pain, but ER Dr said that I didn't need any more tests since it was negative

99.5% of time, nothi. The D-Dimer, if negative, does a fairly good job of ruling out DVT/PE, but isn't absolute (no test is absolute 4 everything). 99.5% of the time a neg D-Dimer means no DVT/PE. (But 1 out of 200+ times it could be falsely reassuring). Not knowing ur specific condition, it's reasonable to look elsewhere 4 the cause of ur symptoms (chest, calf pain) w/ other tests perhaps. TTY regular doc about it. Read more...
Essentially yes. A D-dimer can have a lot of false positive results, but few false negatives. Someone who doesn't have any other risk factors for a blood clot, such as obesity, cancer, a blood clotting disorder (called a hypercoagulable state), or others, may not need another test. Someone who has worrisome risk factors or exam may warrant one, such as an ultrasound of the leg veins or a CT of the chest. Read more...