What Is Tolerance?

Tolerance describes how a person responds to drugs or alcohol over repeated exposures. Over time and with repeated use, a person can have a decreased response to the same amount of a drug or to alcohol. That is due to the development of tolerance.

Tolerance is not the same as being addicted or physically dependent. Tolerance develops when it takes a larger amount to give the same effect as expected.

What Causes Tolerance?

Alcohol tolerance and drug tolerance have similar mechanisms of development. Many different factors can have an impact on the development of tolerance and can be highly individualized to the person and their usage patterns, including:

  • Weight
  • Regularly ingested amount of the substance
  • Gender
  • Age
  • Potency of the substance
  • Contents of stomach
  • Physical and emotional mindset

Functional tolerance is a behavioral adaptation in the brain of someone who chronically uses drugs or alcohol. Their behaviors change upon ingestion of the substance; however, their blood alcohol or drug level content is unchanged.

An interesting independent factor that influences tolerance is familiarity with the location of the drug or alcohol use. This occurs as “standard” amounts of the substance may vary due to different perceptions, recipes, and the tolerance levels of people in that location. For example, if someone drinks their usual drink order in a new location, they may feel the effects of alcohol quicker than they might at home.

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Signs Of A High Tolerance

Higher levels of tolerance can be related to ingesting larger amounts of drugs or alcohol to receive the same desired level of effect. Some other behavior changes that may indicate the development of tolerance to drugs or alcohol are:

  • Increasing the amount of alcohol or drugs used while maintaining the same behaviors.
  • Adjusting food intake to allow for more effect of alcohol (someone may avoid eating so the food doesn’t absorb the alcohol).
  • Friends or family members notice the person seems sober after drinking several drinks.
  • Physical signs of impairment not being noticeable even after multiple drinks or doses of a drug.

What Is The Difference Between Tolerance And Dependence?

Drug or alcohol dependence is a situation in which the person requires either drugs or alcohol to function normally. Dependence can also be associated with withdrawal symptoms developing when the normal amount is not available to the person who is dependent.

The difference between tolerance and dependence relates to the development of withdrawal symptoms with dependence. Dependence describes a need of the body to receive these substances to avoid reacting to the loss of those agents. Tolerance does not describe the body needing drugs or alcohol.

What Is Withdrawal?

Withdrawal describes a range of physical symptoms when the body is not receiving the amount of drugs or alcohol it has become dependent on. Withdrawal can happen in a wide variety of timeframes depending on the substance being chronically used.

At times, withdrawal can be extremely unpleasant, leading the person to use again to avoid these unpleasant feelings. This can create a cycle of increasing usage to prevent withdrawal, increasing tolerance, dependence, and possibly addiction.

What Is The Difference Between Tolerance And Addiction?

Tolerance describes the changing individual perception of being affected by drugs or alcohol. Addiction is a medical condition characterized by continuing to engage in problematic behaviors regardless of consequences. Increasing tolerance can happen without addiction but can be a risk factor for developing a substance use disorder over time.

What Are The Risks Of Developing Tolerance?

The body’s normal warning signals are mistakenly turned off when tolerance develops. This means that harm and impairment still occur, just without as much awareness. Typical warning signs of impairment, such as vomiting, loss of consciousness, or significantly decreased reaction time, can be reduced, making the person feel more in control than they are.

In addition, a reduction of the effects of alcohol intoxication is associated with a faster progression to and worse severity of alcohol use disorder (AUD). Increasing tolerance to the point at which the person inadvertently becomes dependent on alcohol to feel normal is a risk factor for increasing alcohol tolerance.

In short, the biggest risk of developing tolerance is continuing to ingest more drugs or alcohol to reach a desired feeling. Over time, this could lead to dependence and addiction.

Wondering If It’s Time To Get Help?

If you feel like you have an increased tolerance to drugs or alcohol and are worried it could turn into a substance use disorder, it may be time to talk to someone.

Explore our rehab directory or contact a treatment provider to get the help you need before things progress.