For months, the teenager had been using cannabis regularly.
Then the vomiting began.
What initially looked like a severe stomach problem eventually became something far more concerning. After repeated episodes of nausea and vomiting, the teen began experiencing neurological symptoms—including problems with balance, speech, vision, and mental clarity.
Doctors eventually discovered that the prolonged vomiting had depleted his body of an essential nutrient his brain desperately needed: vitamin B1, also known as thiamine.
The result was a potentially dangerous neurological condition called Wernicke encephalopathy.
The unusual case highlights a cannabis-related condition that many families still know very little about: cannabinoid hyperemesis syndrome, or CHS.
And as cannabis products become increasingly potent and accessible, physicians are seeing the condition more frequently in adolescents.
It Started With Persistent Vomiting
The case, published in JPGN Reports, involved a 16-year-old boy who had been inhaling cannabis daily for several months.
He initially arrived at a pediatric emergency department after approximately two weeks of:
- Severe nausea
- Repeated vomiting
- Abdominal pain
Doctors suspected cannabinoid hyperemesis syndrome.
He received fluids and medication for nausea and was advised to stop using cannabis.
But his problems did not end there.
Approximately two months later, he returned to the hospital with symptoms that were much harder to explain.
This time he was experiencing slurred speech, dizziness and changes in his vision.
Blood tests showed electrolyte abnormalities, and he had also developed acute kidney injury that physicians believed was related to dehydration.
Soon, however, his neurological symptoms became even more concerning.
His Brain Began Showing Warning Signs
Despite treatment with intravenous fluids, the teenager continued vomiting.
His neurological symptoms progressed to include:
- Difficulty speaking clearly
- Confusion and altered mental status
- Poor coordination
- Blurred vision
- Difficulty walking normally
- Abnormal eye movements
An MRI revealed changes involving areas of the brain called the medial thalami, raising concern for cerebral edema.
Doctors began considering a diagnosis that is more commonly associated with severe alcoholism than teenage cannabis use: Wernicke encephalopathy.
Testing later revealed that his vitamin B1 level was extremely low.
That clue changed everything.
What Is Wernicke Encephalopathy?
Wernicke encephalopathy is a neurological disorder caused by severe thiamine deficiency.
The brain relies heavily on thiamine to help convert nutrients into usable energy.
When the body becomes severely deficient, certain areas of the brain can malfunction.
Classic symptoms include:
- Confusion
- Difficulty walking or maintaining balance
- Abnormal eye movements
- Vision problems
- Coordination difficulties
Not everyone develops all three classic features at once, which can make the condition difficult to recognize.
Without timely treatment, neurological injury can become severe.
Wernicke encephalopathy is often associated with alcohol use disorder because chronic alcohol consumption can interfere with thiamine absorption and storage.
But alcohol is not the only cause.
Any condition that causes prolonged vomiting, malnutrition or severely reduced food intake can potentially deplete thiamine stores.
That includes severe cannabinoid hyperemesis syndrome.
The Vitamin Treatment Made a Remarkable Difference
Doctors treated the teenager with intravenous thiamine.
According to the published case report, he experienced marked improvement within approximately 48 hours.
He received high-dose IV thiamine for several days followed by continued supplementation.
The combination of his neurological symptoms, MRI findings, very low vitamin B1 level and response to thiamine helped confirm the diagnosis.
The case demonstrates just how quickly repeated vomiting can become more than a gastrointestinal problem.
What Is Cannabinoid Hyperemesis Syndrome?
Cannabis is often associated with reducing nausea.
That makes cannabinoid hyperemesis syndrome seem almost contradictory.
But in some people who use cannabis regularly—particularly over prolonged periods—the opposite reaction can develop.
CHS causes recurring episodes of:
- Severe nausea
- Repeated vomiting
- Abdominal pain
- Loss of appetite
- Dehydration
- Weight loss
Some patients vomit many times per day.
A particularly unusual clue is that people with CHS often discover that very hot showers or baths temporarily relieve their symptoms.
Researchers do not yet completely understand why CHS develops in some cannabis users but not others.
The syndrome is increasingly being recognized among adolescents as well as adults. A 10-year pediatric case series involving patients aged 13 to 20 found patterns including cyclic vomiting, abdominal pain and symptom relief from hot bathing.
Why Cannabis Can Cause Vomiting Instead of Preventing It
Cannabis contains compounds known as cannabinoids, including THC.
Cannabinoids interact with receptors throughout the brain and gastrointestinal system.
At certain doses, cannabis can reduce nausea—which is one reason cannabinoid medications have been investigated or used in some medical settings.
But chronic exposure appears capable of disrupting these same regulatory systems in susceptible people.
Exactly how this happens remains under investigation.
One theory involves changes to cannabinoid receptors after prolonged exposure. Researchers have also examined possible effects on gastric emptying, temperature regulation and the body’s stress-response systems.
Whatever the mechanism, the clinical pattern is becoming increasingly familiar to emergency physicians.
The paradox is important:
A substance someone believes is helping their nausea may actually be perpetuating it.
The Hot-Shower Clue
One of the strangest characteristics of CHS is compulsive hot bathing.
Some people report taking multiple extremely hot showers throughout the day because the heat temporarily reduces nausea or abdominal discomfort.
This behavior is not proof of CHS, but physicians often consider it an important clue when it appears alongside:
- Regular cannabis use
- Recurrent unexplained vomiting
- Abdominal discomfort
- Repeated emergency visits
If the vomiting repeatedly returns and conventional gastrointestinal testing finds no clear explanation, discussing cannabis use openly with a healthcare provider can be crucial.
Why Weeks of Vomiting Can Become Dangerous
Persistent vomiting affects much more than the stomach.
The body can rapidly lose:
Fluids
Severe dehydration can reduce blood flow to the kidneys and potentially cause acute kidney injury.
Electrolytes
Vomiting can disturb potassium, sodium, chloride and other important electrolytes involved in nerve, heart and muscle function.
Calories and protein
Repeated inability to eat can lead to significant weight loss and muscle breakdown.
Vitamins
Water-soluble vitamins—particularly thiamine—may become depleted when food intake remains extremely low.
When thiamine deficiency becomes severe enough, the nervous system and brain may begin to suffer.
That is what made this adolescent case particularly concerning.
Cannabis and the Developing Teenage Brain
CHS is not the only reason physicians caution against frequent cannabis use during adolescence.
The brain continues developing into the mid-20s.
According to the CDC, adolescent cannabis use has been associated with difficulties involving:
- Memory
- Attention
- Learning
- Coordination
- Problem-solving
The risks tend to increase with earlier initiation and more frequent use.
Modern cannabis products can also contain considerably higher concentrations of THC than products available decades ago.
This means today’s exposure patterns may not necessarily resemble those experienced by previous generations.
Can Herbs or Natural Remedies Treat CHS?
When nausea appears, people often reach for ginger tea, peppermint, electrolyte drinks or other traditional stomach remedies.
Some of these may soothe mild digestive discomfort.
But persistent vomiting linked to CHS is different.
There is currently no herb, supplement, detox drink or natural remedy proven to eliminate cannabinoid hyperemesis syndrome while cannabis use continues.
The most important long-term treatment is cessation of cannabis.
Supportive medical treatment may include intravenous fluids, correction of electrolyte abnormalities and medications to control symptoms.
If prolonged vomiting has caused nutritional deficiencies, those deficiencies may also require medical treatment.
In cases where thiamine deficiency or Wernicke encephalopathy is suspected, physicians may administer thiamine promptly rather than waiting for laboratory confirmation because neurological damage can become serious.
Warning Signs That Should Never Be Ignored
Anyone with repeated vomiting—whether or not cannabis is involved—should seek medical attention if symptoms become severe or persistent.
Particular warning signs include:
- Inability to keep liquids down
- Very little or no urination
- Severe weakness
- Confusion
- Difficulty walking
- Slurred speech
- Vision changes
- Fainting
- Severe abdominal pain
- Rapid heartbeat
- Significant unexplained weight loss
Neurological symptoms developing after prolonged vomiting should be treated as particularly concerning.
The Bigger Lesson
The most striking part of this case is not simply that cannabis caused vomiting.
It is the chain reaction that followed.
Regular cannabis use contributed to recurrent vomiting.
The vomiting contributed to dehydration and poor nutrition.
Poor nutrition depleted thiamine.
And severe thiamine deficiency began affecting the brain.
Fortunately, the teenager improved after doctors recognized the problem and administered thiamine.
But the outcome could have been different if the warning signs had been missed.
Cannabis hyperemesis syndrome remains unfamiliar to many people, including teenagers who may believe cannabis is incapable of producing severe vomiting.
As awareness grows, the message is becoming clearer:
Repeated vomiting in a regular cannabis user should not simply be dismissed as a stomach bug.
Sometimes the stomach symptoms are only the beginning.
