The bulging veins on the hand and a little pain may be caused by external stimulation, phlebitis, varicose veins, etc. It is recommended to consult a doctor in time. 1. External stimulation: If the hand is hit by external force, the injury may cause vascular spasm, contraction, and thus the veins on the hand bulge, blue, swelling and pain and other symptoms. 2. Phlebitis: refers to acute aseptic inflammation of venous blood vessels, which can be caused by drugs, infections, hyperlipidemia, etc. It is often manifested as local pain, redness, swelling and other symptoms, and can be touched with painful cord-like stiffness or bead-like nodules. 3. Varicose veins: It refers to the manifestation of vein tortuosity and dilatation caused by the weak wall of vein tubes and blood stagnation, etc. It may manifest as soreness, swelling, pain, and earthworm-like varicose of superficial blood vessels, which protrudes out of the skin, etc. The veins on the hands bulge and become slightly swollen. The bulging of veins on the hands with a little pain may be related to varicose veins. The presence of these factors should lead to prompt medical attention, a clear diagnosis and, if necessary, appropriate treatment.