Addiction is a progressive disease that worsens and becomes more severe over time. In the early stages, people who become addicted will experience mild problems or consequences related to their use. If they escalate their use, these problems and consequences will become more severe, and can include things like:
- Legal problems or consequences
- Impairments at work or job loss
- Financial debts or instability
- Loss of important relationships
- Inability to function independently
- Worsened physical health
- Symptoms of mental illness, including depression or anxiety
A person who has developed an addiction to an opioid drug will almost certainly experience physical symptoms of withdrawal if they cut back or suddenly stop using. These symptoms can last a few days to a week or more and can include:
- Muscle and bone pain
- Nausea and vomiting
- Diarrhea and loose stools
- Insomnia and restless leg syndrome
- Hot and cold flashes
- Severe drug cravings
By far the most serious risk associated with opioid use is the risk of fatal overdose. People who consume too much of an opioid can experience respiratory depression that can lead to death.
These symptoms can be reversed with immediate administering of the medication naloxone, which is carried by most first responders. Private citizens can also obtain naloxone to give an emergency dose as needed to a loved one they know struggles with opioid addiction.
Signs of overdose that require immediate medical attention include:
- Pale, clammy skin
- Limp body
- Blue or purple fingernails or lips
- Vomiting or gurgling noises
- Unresponsive or unable to speak
- Slowed or stopped breathing or heartbeat
Opioid addiction is the result of a complex combination of lifestyle, environmental, and genetic factors. 
Some of the factors that can increase the risk of opioid addiction include:
- Easy access to prescription opioids, legally or illegally.
- Previous history of substance use disorders.
- Anxiety, depression, or other psychiatric illnesses.
- Abuse or neglect during childhood.
- Personality traits, such as sensation-seeking behavior, poor decision-making, disinhibition, and impulsivity.
- Socioeconomic conditions (living in a poverty-stricken area and associating with others who have opioid addiction increases a person’s risk of developing opioid use disorder).
Also, a family history of opioid abuse increases a person’s risk of developing an opioid addiction. The Harvard Twin Study of Substance Abuse by Tsuang et al. found that genetics has a moderate contribution to opioid abuse and dependence. 
Short- and Long-Term Effects of Opioid Addiction
Prescription opioid medications reduce pain and produce feelings of relaxation and happiness. They are extremely useful in managing pain but can have many unwanted, even dangerous effects. Some of the side effects of opioid pain pills include:
- Confusion or mental fog
- Slowed breathing
Long-term use of opioids can lead to a variety of health problems involving the respiratory, cardiovascular, gastrointestinal, musculoskeletal, immune, endocrine (hormonal), and central nervous systems. 
The most dangerous effect of opioids is slowed breathing, which can lead to hypoxia (lack of oxygen supply) in the brain. This can result in short- and long-term neurological and psychological effects, including permanent brain damage, coma, and death.
Other adverse effects of opioid abuse and addiction include:
- Various health problems.
- Failure to meet work/school and family responsibilities.
- Impaired judgment from drug use, leading to risky behaviors, such as unprotected sex.
- Shared drug-injection equipment increases the risk of contracting infections like HIV.
- Prescription opioids are similar in chemical structure to the illegal drug heroin. Some people who misuse opioid medicines switch to heroin because it is cheaper and easier to obtain. An estimated 80% of heroin users say they first misused prescription opioids and later transitioned to heroin. 
Last updated: November 15, 2022
|↑1||Baldini A, Von Korff M, Lin EH. A Review of Potential Adverse Effects of Long-Term Opioid Therapy: A Practitioner’s Guide. Prim Care Companion CNS Disord. 2012;14(3):PCC.11m01326. doi:10.4088/PCC.11m01326|
|↑2||Mistry CJ, Bawor M, Desai D, Marsh DC, Samaan Z. Genetics of Opioid Dependence: A Review of the Genetic Contribution to Opioid Dependence. Curr Psychiatry Rev. 2014;10(2):156-167. doi:10.2174/1573400510666140320000928|
|↑3||Mistry CJ, Bawor M, Desai D, Marsh DC, Samaan Z. Genetics of Opioid Dependence: A Review of the Genetic Contribution to Opioid Dependence. Curr Psychiatry Rev. 2014;10(2):156-167. doi:10.2174/1573400510666140320000928|
|↑4||Baldini A, Von Korff M, Lin EH. A Review of Potential Adverse Effects of Long-Term Opioid Therapy: A Practitioner’s Guide. Prim Care Companion CNS Disord. 2012;14(3):PCC.11m01326. doi:10.4088/PCC.11m01326|
|↑5||Carlson RG, Nahhas RW, Martins SS, Daniulaityte R. Predictors of transition to heroin use among non-opioid dependent illicit pharmaceutical opioid users: A natural history study. Drug Alcohol Depend. 2016;160:127-134. doi:10.1016/j.drugalcdep.2015.12.026|