Complications vary with the vessels involved in the malformation. More complications tend to occur when the malformation is large and when more types of vessels are involved. Lymphatic blebs (blister-like lesions) may leak lymphatic fluid or bleed. Abnormal lymphatic vessels increase the risk of infection in the area of the malformation. Abnormal veins may cause pain, swelling, clotting problems, or heaviness of the affected limb.
In combined lesions with an arteriovenous malformation, the major concerns are due to the abnormal flow of blood from arteries into veins. Normally, blood does not flow directly from an artery to a vein. This may cause pain, skin breakdown, tissue loss and/or overgrowth the affected area on the body. Combined lesions with arteriovenous malformation may lead to heart failure.