Understanding Severity


Like other chronic illnesses, substance use disorders (SUDs) tend to get worse over time, causing more harm to the patient. And similar to the stages of cancer, health care providers measure the severity level of a SUD to help determine the right kind of treatment.

In 2013, doctors released new guidelines for diagnosing SUDs that included three levels of severity: mild, moderate, and severe (also known as addiction). Severity is based on three categories of symptoms related to:


How much control you have over your substance use, such as:

• using more of a substance or more often than you intend to;

• wanting to cut down or stop using but not being able to.


How substance use affects your life, such as:

• neglecting responsibilities and relationships;

• giving up activities you used to care about because of your substance use.


Your level of physical dependence on the substance, such as:

• needing more of the substance to get the same effect (also known as tolerance);

• experiencing withdrawal symptoms when you don’t use.


As a SUD progresses health risks go up. Mental health issues and suicidal thoughts can increase; physical health problems tend to get worse, and overall quality of life goes down. Most importantly, the risk of death increases with severity, which is why starting treatment as soon as possible is so important.


Knowing the severity level helps care providers understand the status of the illness and a patient's risk for serious events (like an overdose) in order to plan the best course of treatment.  The more severe the disorder, the more intense the level of care is needed.


Treatment needs to match the severity level in order to be effective—more treatment isn’t necessarily better if it’s the wrong kind. For example, residential inpatient treatment may help a patient diagnosed with severe SUD, but wouldn’t be appropriate for a patient with mild SUD and could actually cause more harm than good.


As a patient moves through treatment, they will step down to lower levels of care. Their plan should be closely monitored by a care provider and adjusted as needed. If they experience a setback, they may need to go back up a step.


Research has shown that, in general, the longer a person receives treatment, the better their outcomes.