What Is the Clinical Opiate Withdrawal Scale?

The Clinical Opiate Withdrawal Scale, or COWS, is a numbered scale designed to help clinicians tailor opioid withdrawal treatment to individual people. It is used in both in inpatient and outpatient rehabilitation settings to determine the severity of opioid withdrawal and monitor how symptoms change over time during treatment.

We’ll explain what COWS is, symptoms, and how to get treatment for you or a loved one living with addiction.

Clinical Opiate Withdrawal Scale Symptoms

The clinical opiate withdrawal scale uses 11 common symptoms of opioid withdrawal and measures their severity. Typically, symptoms of opioid withdrawal feel like a cold or the flu, but other measures like pulse or blood pressure can help a clinician monitor the severity of the experience.

The 11 withdrawal symptoms measured as part of COWS are:

  1. Resting pulse rate: 80 or below, 81-100, 101-120, or greater than 120 beats per minute
  2. Gastrointestinal upset: based on symptoms from the past 30 minutes and rated as no symptoms, stomach cramps, nausea or loose stool, vomiting or diarrhea, and multiple episodes of vomiting or diarrhea
  3. Sweating: not taking physical activity or room temperature into account and measured over the past 30 minutes; scale includes no chills or flushing, some self-reported chills and flushing, flushed face with observable sweat, beads of sweat on brow or face, and sweat streaming off of face
  4. Tremor: based on the clinician’s observation of the patient’s outstretched hands; measures no tremor, felt but not observed, slight observable tremor, or gross tremor or muscle twitching
  5. Restlessness: measurable through observation, like tremor, and described with able to sit still, difficulty sitting still, frequent shifting of legs or arms, unable to sit still
  6. Yawning: measured as none, once or twice during assessment, three or more times during assessment, and several times per minute
  7. Pupil size: measured based on visual exam, through descriptions pinned or normal size for light, larger than normal for light in room, moderately dilated, and extremely dilated
  8. Anxiety and irritability: predominantly self-reported by the patient, but can be a very useful measure of how the individual experiences withdrawal symptoms; scale rates as none, increasing irritability/anxiousness, obvious irritability/anxiousness, and participation in assessment is difficult due to irritability/anxiety
  9. Bone or joint aches: only related to sensations attributable to opiate withdrawal; measures as none, mild and diffuse discomfort, patient-reported severe aches, and patient visibly rubbing sore joints or muscles during assessment
  10. Goosebumps: measured with descriptions skin is smooth, piloerection (hairs standing up) can be felt but not seen, and piloerection is prominent
  11. Runny nose and watering eyes: measurement only for withdrawal-related symptoms; descriptions for measurement: none present, nasal stuffiness and unusually moist eyes, and nose constantly running with tears streaming down the cheeks

In some clinics, COWS also includes the introduction of buprenorphine during the assessment: whether none was given, or when it was supplied during the assessment and how often.

Each description in the 11-symptom scale has a numerical value, which is tallied to help the clinician understand the severity of withdrawal. Scores of 5-12, for example, indicate mild withdrawal, while a score of 36 or more indicates severe withdrawal.

History of the Clinical Opiate Withdrawal Scale

As heroin addiction became a greater problem in the US and Europe, the COWS scale was developed to measure the severity of the addiction and withdrawal syndrome. COWS is based on the CIWA-Ar (Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised), used to measure alcohol withdrawal in a person with alcohol use disorder. The opioid scale was developed in the 1930s, and since then, many other scales have been developed for opioid withdrawal and other substances of addiction.

COWS is in contrast with another scale, called the Subjective Opiate Withdrawal Scale (SOWS), according to the World Health Organization. This is a self-reported scale in which a clinician interviews a person experiencing opioid withdrawal symptoms to understand the person’s experience of symptoms, including:

  • Sweating.
  • Watering of the eyes.
  • Runny nose.
  • Yawning.
  • Hot and cold flashes.
  • Anorexia, or loss of appetite.
  • Abdominal cramps.
  • Nausea.
  • Vomiting and diarrhea.
  • Shaking or tremor.
  • Insomnia.
  • Restlessness.
  • General aches and pains.
  • Tachycardia.
  • Hypertension.
  • Goosebumps.
  • Dilated pupils.
  • Bowel sounds.

Typically, when using SOWS, a clinician will also measure specific items like hypertension to verify the report. Using a combination of scales can help the clinician to not only understand the experience of withdrawal symptoms but also how their patient experiences them, which could be an indication of cravings, psychological withdrawal, and potential for relapse. Understanding all of these experiences gives rehabilitation professionals a good understanding of how to best help each client individually.

COWS During Medical Detox

COWS is just one tool that treatment professionals use to help people in opioid withdrawal. Based on how the patient is experiencing withdrawal, clinicians are better able to address the physical and psychological discomfort, cravings, and other symptoms that may occur during this time.

While very rarely life-threatening, opioid withdrawal can be intensely uncomfortable and difficult to get through on your own. In a medical detox, specialists are on hand to help manage withdrawal symptoms and make the process as safe and comfortable as possible.

Opioid Detox is Las Vegas

If you or someone you love is struggling with opioid addiction, we can help. At our inpatient rehab in Las Vegas, NV we get people on the road to recovery and living a life they deserve. Our caring and compassionate treatment specialists use evidence-based addiction-focused healthcare to treat people living with substance use disorders, including opioids.

Contact our knowledgeable and helpful admissions navigators at to learn more about the different levels of care at Desert Hope, including inpatient, outpatient, and sober living, and to start admissions. Our navigators can answer your questions about using insurance for rehab or other ways to pay for addiction treatment.

Recovery is possible, so don’t wait. Call or text us today.

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