What Happens During Medical Detox? A Step-by-Step Guide

Most people picture detox as something to get through. A well-run unit treats it as something staff manage, on a schedule, by the numbers.

Here is that schedule. Timing varies by program and by substance, and the steps blur into each other, but the order holds.

Before you arrive

The phone screening comes first: what you use, how much, when you last used, past withdrawal seizures, medications and health history. Answer it honestly, because the medication plan starts from those answers. Bring photo ID, your insurance card, and prescriptions in their original bottles; the full list is in what to bring to detox. If you drink heavily every day or take benzodiazepines, do not quit abruptly on your own while you wait for an admission time.

Step 1: Admission and assessment

Intake usually takes a few hours. A nurse and physician review your medical history, substance use, medications, and mental health. You will have vitals taken, a physical, and a urine drug screen. Expect your bag to be checked and any medications logged. If you are new to the idea of detox itself, start with What Is Medical Detox? Everything You Need to Know.

The assessment ends with a baseline withdrawal score. For alcohol that is usually the CIWA-Ar, a 10-item scale covering symptoms such as tremor, sweating, anxiety, agitation and disorientation. For opioids it is usually the Clinical Opiate Withdrawal Scale, or COWS. A higher score means worse withdrawal. Every decision after this point refers back to that number.

Step 2: Stabilization

Withdrawal medications begin, usually within the first few hours. What you get depends on what you are coming off.

• Alcohol. Often a benzodiazepine taper guided by the CIWA-Ar scale. ASAM names benzodiazepines as first-line for moderate and severe alcohol withdrawal and says longer-acting ones are preferred. Thiamine is given to prevent Wernicke encephalopathy, a brain injury caused by thiamine deficiency.
• Opioids. Typically buprenorphine, started once withdrawal is measurable on the COWS scale, or methadone. With fentanyl in the picture, timing takes more care; see precipitated withdrawal.
• Benzodiazepines. Tapers work differently, more slowly, and often with a long-acting benzodiazepine; see Xanax Withdrawal Is Not Something to Push Through Alone.

If you already take buprenorphine, methadone, or psychiatric medication, say so at intake and bring the bottles. A detox stay is not a reason to stop a medication that is working. If you take methadone, the program will usually need to confirm your dose with your opioid treatment program before continuing it. Ask on the first call whether the program continues medications you already take.

Fluids, electrolytes, and thiamine correct the deficiencies that make people feel worst. Comfort medication for nausea, diarrhea, aches and sleep fills the gaps.

Step 3: Peak withdrawal and monitoring

The 24 to 72 hour window is the most intensive. Nurses repeat vitals and the withdrawal score on a schedule, every few hours. They adjust medications and manage sleep, anxiety, and nausea. ASAM’s alcohol guideline calls for reassessment every 1 to 4 hours for the first 24 hours while withdrawal is moderate to severe.

Alcohol seizure risk peaks here: seizures are most likely 12 to 48 hours after the last drink. Delirium tremens, when it happens, comes later, most often 48 to 96 hours in, and can develop in someone who appeared to be improving. That is why a good unit does not relax on day two. Opioid symptoms (body aches and gastrointestinal distress) peak and then decline.

This is often when the urge to leave hits hardest. An adult can almost always leave. Our guide to leaving detox early covers what it costs, by substance.

Step 4: Recovery, groups, and planning

Once symptoms settle, days three through five focus on rest, light group programming, and building the discharge plan. Case managers verify insurance for next-level care: residential, PHP, IOP, or outpatient with MAT.

This step is what makes detox more than a place to wait out withdrawal. SAMHSA’s protocol on detoxification counts getting the person ready to enter treatment as one of the three parts of the job. For alcohol, ASAM says treatment for the drinking itself should start during detox once the person is clear-headed enough, and three medications are approved for alcohol use disorder: naltrexone, acamprosate and disulfiram. For opioids, ASAM’s practice guideline calls ongoing medication the standard of care, so the medication you were stabilized on is often the one to keep.

Step 5: Discharge to the next level of care

A safe discharge is the whole point. You leave with a written plan, a first appointment already scheduled, medications in hand where appropriate, and naloxone if opioids were involved.

The days after discharge carry their own risk. After opioid detox, tolerance is lower than before, so a former dose can be an overdose. MedlinePlus calls a return to use the biggest complication of opioid withdrawal, because someone who has just detoxed can overdose on a much smaller dose than before. Keep naloxone where someone else can find it, and do not use alone.

If you are still deciding whether detox is the right step, read How Do You Know When Someone Needs Detox? before you call. For what comes next, see what comes after detox.

What a day inside looks like

The rhythm is set by the withdrawal scores. Expect vital signs and a score in the morning, medication on a schedule with extra doses when the score calls for them, meals you may not want for the first day or two, and a lot of sleep. As symptoms ease, there is usually a group or two a day, time with a counselor or case manager, and visits from the physician.

House rules vary by program, and it is worth asking about them before you arrive. Common ones:

• Phones may be held for the first days, so bring important numbers on paper
• Visitors may be limited or scheduled
• Bags are searched, and medications are logged and handed out by staff
• Nothing containing alcohol, including some mouthwash and hand sanitizer

None of this is punishment. Most of it exists because withdrawal makes judgment unreliable for a few days.

What family can do during the stay

Less than they want to, and more than they think. Ask the person for written permission to talk with staff; privacy law limits what a program can tell you without it. Fill in history the person may not remember, especially past withdrawal seizures, which ASAM’s guideline says family can help establish. Be ready for a call asking to come home in the first few days, and decide ahead of time what you will say. The family guide covers it.

How long the whole thing takes

Most stays run three to seven days. In New Jersey’s 2024 state treatment data, the median stay in residential detox was 7 days, across all substances. Methadone and other long-acting drugs take longer. Outpatient detox follows the same steps in daily visits, with you sleeping at home; our outpatient detox guide explains who it suits.