When you or someone you love is thinking about detoxing from drugs or alcohol, you might have thought about will their blood pressure and detox, and will it be an issue. During the prescreen to a detox there will be a medical history taken, and when they ask about your blood pressure, this can be scary.
Here’s the simple truth: blood pressure often changes during detox. Sometimes it goes up. Sometimes it goes down. Neither one means something is wrong with you as a person. It means your body is adjusting to a big change, and it’s one of the main things a good detox team watches closely.
We asked Renee King, one of our providers at Liberty, to give us some information on what she has been seeing and what she worries about most when it comes to detox and blood pressure.
Why Does Blood Pressure Go Up and Down in the First Place?
Think of your nervous system as having an “alarm” setting. When your body senses danger — real or not — that alarm speeds up your heart and tightens your blood vessels. That’s what pushes blood pressure up.
Alcohol and many other substances quiet that alarm down while you’re using them. Your body gets used to running with the alarm turned low. When you stop, the alarm can swing the other way and get stuck “on” for a while. That’s why blood pressure often climbs in the first few days of withdrawal.
The opposite can happen too. If someone hasn’t been eating or drinking enough water — which is common before someone comes in for detox — there isn’t enough fluid moving through the blood vessels, and pressure drops instead.
Why does any of this matter? Blood pressure that swings too high, even for a short time, puts extra strain on the heart and raises the risk of serious problems like stroke. Blood pressure that drops too low can cause dizziness, fainting, or falls. Neither extreme is common, and most changes during detox are temporary — but they’re exactly the kind of thing a medical team needs to catch early, before they become emergencies.
“It Depends on What You’re Detoxing From”
That’s how Renee starts every answer to this question, and it’s the most honest place to begin. Blood pressure doesn’t move the same way for every substance.
“It really depends on what substance you’re detoxing from,” said Renee King, a provider at Liberty Health Detox.
Alcohol
“We worry about autonomic instability and a hyperactive nervous system during withdrawal, which can lead to increased blood pressure,” King explained.
In plain language, that “alarm system” gets stuck on high alert once alcohol is out of the picture. This isn’t just something we’ve noticed at Liberty — researchers have measured it directly. One study followed heavy drinkers with high blood pressure and tracked what happened after they stopped drinking. Their blood pressure came down, and it came down fast, often within the first couple of weeks (Soardo et al., 2006, Journal of Hypertension). Other research has found similar patterns: in one study, more than half of alcohol-dependent patients had high blood pressure while they were still drinking, and that number dropped sharply within weeks of stopping.
That’s good news in the long run. But in the first few days, it’s exactly why blood pressure needs to be checked often, not just once at intake.
Medetomidine
“This is a newer emerging substance that can also cause increased blood pressure during detox,” King said. “Close monitoring is important because symptoms can escalate quickly, and we need to be able to provide a higher level of care, including ICU-level care if necessary.”
Medetomidine is a sedative made for animals, not people, and it’s never been approved for human use. Over the past couple of years, it’s started turning up mixed into street fentanyl in several U.S. cities. Health officials first spotted it in 2022, and by late 2024 it was showing up in the majority of tested fentanyl samples in some cities. Withdrawal from it doesn’t behave like typical opioid withdrawal — it can start within hours of last use, and blood pressure can climb quickly and severely. In one group of patients tracked across several Philadelphia hospitals, most needed intensive, hospital-level care to get through it safely.
This is exactly why King’s team treats it with extra caution, and why detoxing from it alone at home carries real risk — the warning signs can move faster than a person can react to on their own.
What About Other Substances?
Alcohol and medetomidine aren’t the only substances that can move blood pressure during detox. A few others are worth knowing about too.
Benzodiazepines (like Xanax, Valium, and Klonopin) work on the same part of the brain as alcohol, so withdrawal looks similar in a lot of ways. The same “alarm system” gets stuck on, and that can mean higher blood pressure, a faster heart rate, sweating, and shaking. According to the American Academy of Family Physicians, this “autonomic instability” is a well-known part of benzodiazepine withdrawal, which is exactly why it’s treated with the same level of caution as alcohol withdrawal.
Opioids (like heroin, fentanyl, and prescription painkillers) work differently, but withdrawal still tends to push blood pressure up. Research summarized on the National Institutes of Health’s StatPearls resource shows that opioid withdrawal is rarely life-threatening on its own, but it does involve a real jump in blood pressure and heart rate as the body’s stress response switches back on. That’s part of why medications like clonidine are often used to help ease people through it safely.
Stimulants (like cocaine and methamphetamine) work in the opposite direction from what you might expect. It’s actual use, not withdrawal, that raises blood pressure the most — sometimes sharply. The American Heart Association has reported that methamphetamine use alone can raise both heart rate and blood pressure enough to cause lasting strain on the heart over time. Withdrawal from stimulants tends to look different — more of a “crash” with exhaustion and low mood — but the cardiovascular effects of the use itself are exactly why a full medical picture matters going into detox, not just what’s happening on day one.
Nutrition and Hydration
“Nutritional and hydration status would cause blood pressure to be low,” King noted.
Blood is mostly water. When the body doesn’t have enough fluid on board, there’s less volume moving through the blood vessels, and pressure falls. That can show up as dizziness, feeling faint, or feeling unusually tired. It’s one more reason a real meal plan and steady fluids are part of detox from day one, not an afterthought.
Already Have High Blood Pressure? Here’s What You Should Know
If you already take medication for high blood pressure, or you’ve been told your numbers run high, it’s completely normal to be extra worried about detox. Here’s the honest answer: yes, your starting point matters, and your team needs to know about it before day one.
If your blood pressure is already elevated, the temporary rise that can happen during withdrawal is starting from a higher baseline — which is exactly why your care team will watch you more closely, not less. This isn’t something to hide or downplay when you come in. Tell your provider about every blood pressure medication you’re on, how long you’ve had high blood pressure, and any past problems like a hypertensive emergency. That information changes how closely you’re monitored and whether your medication needs adjusting during your stay.
The goal isn’t to scare you into thinking detox is off-limits because of your blood pressure history. It’s the opposite: knowing your history in advance is exactly what makes it safe to move forward.
Why This Matters, Even If You Never See a Number
You may never see your own blood pressure reading during detox, and that’s fine. The number itself isn’t the point. The point is that someone is watching it, several times a day, so that if it starts moving in a dangerous direction, your care team can act before it becomes an emergency instead of after.
That’s the real difference between detoxing on your own and detoxing with medical support: not just comfort, but someone catching the moment your body needs help.
A Few Honest Answers
Does this mean I have heart problems? Not usually. Blood pressure changes during withdrawal are mostly temporary. They’re your body reacting to a substance leaving its system, not a sign of permanent heart disease. Your team will tell you plainly if anything looks like it needs follow-up care after detox.
I already have high blood pressure. Should I be more worried than most people? More alert, yes — more worried, not necessarily. It just means your team needs your full history upfront so they can watch you more closely from day one.
Will I be put on blood pressure medication forever? Not automatically. Some people need short-term medication just to get through withdrawal safely. Whether anything continues afterward depends on your own numbers and history, and that’s a conversation with your provider, not a default.
What if my blood pressure gets dangerously high? That’s exactly what round-the-clock monitoring is for. If numbers move into a dangerous range, the team escalates care right away, which can include additional medication, closer monitoring, or, in serious cases like medetomidine withdrawal, a higher level of care.
Sources
- Soardo G, Donnini D, Varutti R, et al. “Effects of alcohol withdrawal on blood pressure in hypertensive heavy drinkers.” J Hypertens. 2006;24(8):1493-1498. [PubMed: pubmed.ncbi.nlm.nih.gov/16877950]
- Saunders JB, et al., as cited in “Effect of Alcohol Abstinence on Blood Pressure,” Hypertension (AHA Journals): ahajournals.org/doi/10.1161/01.hyp.33.2.653
- CDC MMWR, “Notes from the Field: Suspected Medetomidine Withdrawal Syndrome Among Fentanyl-Exposed Patients — Philadelphia, PA”: ncbi.nlm.nih.gov/pmc/articles/PMC12045483
- Cleveland Clinic, “How Dehydration Affects Blood Pressure”: health.clevelandclinic.org/dehydration-and-blood-pressure
