How common is pain relief medications addiction?

Only a small percentage of people who use prescription pain relief medications develop an addiction, especially if they follow a physician’s orders. People frequently mistake tolerance for addiction. Tolerance may be developed by people who have been taking opioids for a long time, but tolerance and even physical dependence are not the same as addiction. The difference is that tolerance means that the initial dose has lost its effectiveness; dependence is characterized by withdrawal symptoms; and addiction is a psychological and behavioral reaction. In any case, pain drug addiction is indeed a possibility, in particular for individuals who have had a previous history with substance abuse.
What are the most commonly abused pain relief medications?
According to the official website of National Institute on Drug Abuse, the most commonly abused prescription opioids and morphine derivatives are codeine (aka Cody, Captain Cody, and schoolboy), morphine (aka M, Miss Emma, monkey, white stuff), methadone (aka fizzies, and chocolate chip cookies when with MDMA), fentanyl (aka Apache, China girl, China white, dance fever, friend, goodfella, jackpot, murder 8, TNT, Tango & Cash), Oxycodone HCL (aka hillbilly heroin), hydrocodone (aka Vike, Watson-387), hydromorphone (aka juice, smack, D, footballs, dillies), oxymorphone (aka biscuits, blue heaven, blues, Mrs. O, octagons, stop signs, O bomb), meperidine (aka demmies), and propoxyphene. 
The high provided by these pain relief medications is accompanied by pain relief, euphoria, drowsiness, sedation, weakness, dizziness, nausea, impaired coordination, confusion, dry mouth, itching, sweating, clammy skin, and constipation. Additionally, they have potential health complications such as slowed or arrested breathing, lowered pulse and blood pressure, tolerance, addiction, unconsciousness, coma, death; risk of death increased when combined with alcohol or other CNS depressants. 
The best way to prevent addiction is to take prescription drugs exactly as instructed by a certified physician. Moreover, patients should talk with their doctors about any personal and/or family history of substance abuse. Individual who take pain medication should understand that tolerance is normal, and that needing a higher does not mean they have become addicted. Also, people whose pain is of a musculoskeletal nature could give TENS and EMS units (TENS 3000 and 7000, CareTec  IV, EMS 5.0, EMS 7500, Ultrasound US 1000, and others available at Discount Medical Supplies) a chance, and entirely avoid the risk of not only addiction but also side effects related to pain relief medications.