Causes
The direct cause of beriberi is a critically low level of thiamine (vitamin B1). The body requires thiamine to break down carbohydrates for energy and to maintain proper function of the heart, muscles, and nerves. Since the body cannot produce thiamine on its own and stores only small amounts, a continuous dietary supply is necessary to prevent depletion.

Risk Factors
In developed countries, the most common risk factor is alcohol use disorder, as excess alcohol makes it difficult for the body to absorb and store thiamine. Other risk factors include:

• Diets consisting mainly of milled, white rice or highly refined carbohydrates.
• Dialysis treatment for kidney failure, which can filter vitamin B1 out of the body.
• Taking high doses of diuretics (water pills).
• Bariatric surgery or other conditions that impair nutrient absorption.
• Hyperthyroidism (overactive thyroid).
• Extreme nausea and vomiting during pregnancy (hyperemesis gravidarum).
• Genetic beriberi, a rare inherited condition that prevents the body from absorbing thiamine effectively.

Prevention
Primary prevention involves eating a balanced diet rich in whole foods. Thiamine is naturally found in meat, fish, poultry, whole grains, nuts, dried beans, and peas. In many countries, bread and cereal products are fortified with thiamine to prevent deficiency in the general population. For individuals with known risk factors, such as those with heavy alcohol use, doctors may recommend thiamine supplements to reduce the risk of developing the condition.

Signs and Symptoms
Symptoms vary depending on which body system is most affected. Clinicians typically categorize the disease into "wet" and "dry" forms, though patients may experience symptoms of both.

Wet Beriberi (Cardiovascular)
This form primarily affects the heart and circulatory system. It is a medical emergency that can lead to heart failure. Symptoms include:

• Shortness of breath during physical activity.
• Waking up at night short of breath.
• Rapid heart rate (tachycardia).
• Swelling (edema) in the lower legs and feet.

Dry Beriberi (Neurological)
This form damages the nerves and leads to decreased muscle strength. Symptoms include:

• Numbness, tingling, or loss of feeling in the hands and feet.
• Pain in the limbs.
• Difficulty walking or loss of coordination.
• Mental confusion or speech difficulties.
• Involuntary eye movements (nystagmus).
• Vomiting and general weakness.

Wernicke-Korsakoff Syndrome
Severe deficiency can lead to this brain disorder, characterized by confusion, loss of muscle coordination (ataxia), and memory changes. Wernicke encephalopathy is the acute phase, while Korsakoff syndrome involves chronic, often permanent memory loss.

Diagnosis
Doctors diagnose beriberi based on a physical exam and medical history. They may check for signs of heart failure (like swelling and rapid heartbeat) or neurological damage (like drooping eyelids, weak reflexes, or difficulty walking). To confirm the diagnosis, blood and urine tests are used to measure thiamine levels and check how the body is processing nutrients. In some cases, doctors may administer thiamine and observe if symptoms improve, which serves as a confirmation of the diagnosis.

Medical Treatment
The primary treatment for beriberi is replacing the missing thiamine. This is typically done with thiamine supplements. In severe or acute cases, such as wet beriberi or Wernicke encephalopathy, thiamine is administered intravenously (IV) or by injection (IM) in a hospital setting to ensure rapid absorption. For milder cases, oral supplements may be prescribed. Treatment also involves managing complications, such as using medication to support heart function during recovery.

Lifestyle and Management
Long-term management focuses on preventing recurrence. This often involves working with a nutritionist to design a balanced diet that includes thiamine-rich foods like beans, legumes, seeds, meat, and whole grains. For patients with alcohol use disorder, treatment usually includes support for stopping alcohol consumption, as continued drinking will interfere with thiamine absorption.

Monitoring and Recovery
Patients typically require follow-up blood tests to ensure thiamine levels have returned to normal. Physical therapy may be necessary to help regain muscle strength and coordination if nerve damage has occurred. While heart function often recovers quickly, nerve healing can take months.

When to Seek Medical Care
Beriberi can progress rapidly. Seek emergency care if you experience severe difficulty breathing, chest pain, rapid heartbeat, or sudden confusion. Routine medical appointments are important if you have risk factors like kidney dialysis or a history of heavy alcohol use, so your provider can monitor your vitamin levels.

Severity
Beriberi ranges from mild symptoms of fatigue to severe, life-threatening emergencies. Wet beriberi can cause acute heart failure and death within hours or days if left untreated. Dry beriberi can lead to paralysis and severe wasting of the muscles. Wernicke encephalopathy is an acute neurological emergency that carries a high risk of mortality without immediate treatment.

Prognosis and Recovery
With prompt treatment, the prognosis is generally good. Heart damage from wet beriberi is often reversible, and patients may see improvement in heart function within hours of receiving thiamine. Complete recovery is common if the condition is caught early.

Long-Term Effects
Recovery from dry beriberi and neurological damage is slower and may not always be complete. Some patients may experience lasting gait issues or memory problems. If Wernicke encephalopathy progresses to Korsakoff syndrome, the memory loss and cognitive impairment are frequently permanent and require long-term care. Early detection is the single most important factor in preventing irreversible damage.

Impact on Activities
During the active phase of the disease and early recovery, patients may experience significant fatigue, weakness, and mobility limitations. This can make working, attending school, or performing household chores difficult. Patients recovering from heart failure may need to limit physical exertion temporarily. Those with nerve damage may need assistance with walking or tasks requiring fine motor skills.

Mental and Emotional Health
Confusion and memory loss can be frightening for patients and their families. The recovery process can be frustrating, especially if nerve regeneration is slow. Support from family and mental health professionals can be beneficial, particularly if alcohol dependency is a contributing factor.

Questions to Ask Your Healthcare Provider
Bringing a list of questions to your appointment can help you manage your care effectively:

• Is my condition acute, or do I have long-term damage?
• How long will I need to take thiamine supplements?
• Are there specific foods I should eat or avoid to help my recovery?
• Do I need physical therapy to help with muscle weakness?
• How often do I need to come in for follow-up blood tests?
• What are the signs that my thiamine levels are dropping again?
• Can you refer me to a specialist for help with alcohol cessation (if applicable)?

Q: Is beriberi contagious?
A: No, beriberi is a nutritional deficiency caused by a lack of vitamin B1 (thiamine). It cannot be spread from person to person like a virus or bacteria.

Q: Can I get beriberi from eating white rice?
A: Historically, beriberi was common in populations where the diet consisted almost exclusively of polished white rice, which has the thiamine-rich husk removed. Today, this is rare because many white rice products are fortified with vitamins, and most people eat a varied diet. However, a diet limited strictly to unfortified white rice could still pose a risk.

Q: How quickly does treatment work?
A: Improvements can be dramatic. Heart function often improves within hours of receiving intravenous thiamine. However, symptoms related to nerve damage, such as numbness or weakness, may take months to heal, and some memory loss associated with advanced cases may be permanent.

Q: Is beriberi the same as Wernicke-Korsakoff syndrome?
A: They are closely related. Beriberi refers to the general symptoms of thiamine deficiency, often affecting the heart (wet) or nerves (dry). Wernicke-Korsakoff syndrome is a specific, severe complication of thiamine deficiency that affects the brain. It is often seen in association with alcohol misuse.

Q: Can healthy people get beriberi?
A: It is very unlikely for a healthy person with a varied diet to develop beriberi. The body stores small amounts of thiamine, so a healthy diet replenishes it regularly. It is most common in people with specific risk factors that prevent absorption or intake, such as alcohol use disorder, starvation, or specific genetic conditions.