Hi Welcome to HCM Dear , your problem of swollen painful vein on thumb may be due to Carpal tunnel syndrome , the out come of side effect of your trigger thumb problem . Carpal tunnel syndrome is a hand and arm condition that causes numbness, tingling and other symptoms. It may be caused by a pinched nerve in your wrist , results in engorged painful vein on thumb . When veins bulge ,engorged due to the collection of an abnormal amount of blood on the hand or anywhere else in the body -- it is because the blood is pooling in the vein, either due to a problem with the vein itself or an underlying condition . Even if no other symptoms are present other than bulging veins, it does not rule out a more serious medical condition . Regular exercise helps veins work better and lower the likelihood of getting blood clots. Hot pack application helps reduce pain and swelling . Apply a warmed leaf of cabbage on effected swollen part for relief . Eat foods rich in dietary fiber, such as whole grains. Bioflavonoids found in dark berries, dark leafy greens, garlic, cabbage and onions help keep veins healthy. Turmeric powder a level spoon+ a spoon of almond oil with a cup of hot milk at bed time will help alley infecion and pain . Supplements as Aloe vera juice 35 ml + a spoon of Amla juice may help include vitamin C, D vitamin E,K and zinc and lead to healthy disease free life . it is important that you speak with your doctor in case the swelling and pain lasts for some time . Hope this helps solves your query .Take care . All the best Don t hesitate to get back if have any query .