Venous thrombosis affects numerous sites in human beings, and signs and symptoms resulting from its presence are extremely variable. Small veins, large veins, minor tributaries, and major stems show protean effects when they are involved by thrombosis. The causative factors, too, are numerous and extremely variable—blood stasis, changes in known and unknown coagulation factors and trauma, malignancy, systemic diseases: cardiac, pulmonary, hepatic, hematogenous, vascular. These features are important, but the objectives of this discussion will be confined mainly to treatment.

A classification of venous thrombosis may be very useful in discussing the practical aspects of treatment, and with this in view the following is a classification based on anatomic location, degree of involvement, and presence or absence of infection in thrombus.

ClassificationÌý A. Superficial vein thrombosisB. Deep vein thrombosisMildSeverePhlegmasia alba dolensPhlegmasia cerulea dolensC. Septic thrombosisUsing this classification it is possible to segregate the