I have slept on my arm 2 days ago, i now feel pain/tiredness on my shoulder / arm. my upper right and shoulder veins are also are more visible than before when i do some effort but disappear when i don't do anything what should i expect ?

Expect to see doctor: It may be time to see the doctor, either one's primary care doctor now, or the Emergency Room doctor, who will examine the arm and veins to see if there is anything blocking the flow of blood. If a blood clot is suspected, studies such as an ultrasound scan may be needed. Other than a clot, blood may also be blocked by something compressing the vein, which would also need evaluation and treatment.

Possibilities: Possible causes of your arm symptoms include a nerve impingement at the neck or shoulder, tendonitis of the shoulder joint or blood clot in a vein in the arm. If there is any swelling of the arm or hand, blood clot must be checked for. Nerve impingement is more likely if there's no swelling. Your physician can evaluate you and refer you to the proper specialist.