What Is The Main Cause Of High Potassium?

What Is The Main Cause Of High Potassium? High potassium, also known as hyperkalemia, can arise from various factors affecting kidney function, diet, and medication usage, so understanding the principal causes is essential for maintaining overall health. WHAT.EDU.VN offers comprehensive answers to your questions and helps you understand the complexities of this condition. This knowledge supports informed decisions about your health and wellness. Explore conditions like kidney malfunction and potassium imbalances.

1. Understanding High Potassium (Hyperkalemia)

Hyperkalemia, or high potassium, occurs when there’s an excess of potassium in your bloodstream. Potassium is an essential mineral that helps nerves and muscles function properly. Keeping its level balanced is vital for overall health. The normal range of potassium in the blood is typically between 3.5 and 5.0 millimoles per liter (mmol/L). A potassium level higher than 5.5 mmol/L is generally considered high, and levels above 6.0 mmol/L can be dangerous and require immediate medical attention.

1.1. Why Potassium Levels Matter

Potassium is crucial for several bodily functions, including:

Nerve Function: Potassium helps nerves transmit signals throughout the body.
Muscle Contraction: It is essential for muscle contractions, including those of the heart.
Fluid Balance: Potassium helps maintain the balance of fluids inside cells.
Blood Pressure Regulation: It plays a role in keeping blood pressure at healthy levels.

1.2. Symptoms of High Potassium

Mild hyperkalemia may not cause noticeable symptoms. However, when potassium levels rise significantly, symptoms can include:

Muscle Weakness: Feeling weak or heavy in the limbs.
Fatigue: Experiencing unusual tiredness or lack of energy.
Numbness or Tingling: Sensations in the hands and feet.
Nausea and Vomiting: Feeling sick to your stomach.
Chest Pain: Discomfort or pain in the chest.
Heart Palpitations: Feeling that your heart is skipping beats or fluttering.
Difficulty Breathing: Shortness of breath or troubled breathing.

Severe hyperkalemia can lead to life-threatening heart rhythm problems, such as cardiac arrest. If you experience any of these symptoms, seek immediate medical attention.

2. Main Causes of High Potassium

Several factors can lead to high potassium levels in the blood. The most common causes include kidney disease, medications, and dietary habits. Understanding these main causes is essential for preventing and managing hyperkalemia.

2.1. Kidney Disease

Kidney disease is the most prevalent cause of hyperkalemia. The kidneys play a crucial role in regulating potassium levels by filtering excess potassium from the blood and excreting it in the urine. When the kidneys are not functioning correctly, they may not be able to remove potassium efficiently, leading to a buildup in the bloodstream.

2.1.1. How Kidney Disease Leads to High Potassium

Chronic Kidney Disease (CKD): In CKD, the kidneys gradually lose their ability to filter waste and regulate fluids and electrolytes, including potassium. As kidney function declines, potassium accumulates in the body.

Acute Kidney Injury (AKI): AKI is a sudden loss of kidney function that can occur due to various reasons, such as severe dehydration, infections, or certain medications. AKI can impair the kidneys’ ability to excrete potassium, leading to hyperkalemia.

2.1.2. Managing High Potassium in Kidney Disease

Dietary Modifications: Limit potassium-rich foods in your diet, such as bananas, oranges, potatoes, and tomatoes.
Medications: Your doctor may prescribe medications to help lower potassium levels, such as potassium binders that bind to potassium in the digestive tract and help remove it from the body.
Dialysis: In severe cases of kidney disease, dialysis may be necessary to remove excess potassium and other waste products from the blood.

2.2. Medications

Certain medications can interfere with the body’s ability to regulate potassium levels, leading to hyperkalemia. These medications may affect kidney function, hormone levels, or the movement of potassium into and out of cells.

2.2.1. Common Medications That Raise Potassium

ACE Inhibitors and ARBs: Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are commonly used to treat high blood pressure and heart failure. They can reduce the production of aldosterone, a hormone that helps the kidneys excrete potassium.
Potassium-Sparing Diuretics: These diuretics, such as spironolactone and amiloride, prevent the kidneys from excreting potassium, leading to increased potassium levels in the blood.
NSAIDs: Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, can reduce kidney function and increase potassium levels, especially in people with pre-existing kidney disease.
Immunosuppressants: Medications like cyclosporine and tacrolimus, used to prevent organ rejection after transplantation, can impair kidney function and raise potassium levels.
Heparin: This blood thinner can inhibit aldosterone production, leading to potassium retention.
Trimethoprim: An antibiotic that can interfere with potassium excretion by the kidneys.

2.2.2. How Medications Affect Potassium Levels

These medications can affect potassium levels through various mechanisms:

Impaired Kidney Function: Some medications reduce the kidneys’ ability to filter and excrete potassium.
Hormone Interference: Certain drugs interfere with hormones like aldosterone, which regulate potassium excretion.
Potassium Movement: Some medications affect the movement of potassium into and out of cells, causing potassium to accumulate in the bloodstream.

2.2.3. Managing Medication-Induced Hyperkalemia

Review Medications: Regularly review your medications with your doctor to identify any drugs that may be contributing to high potassium levels.
Dosage Adjustments: Your doctor may adjust the dosage of certain medications to minimize their impact on potassium levels.
Alternative Medications: If possible, your doctor may prescribe alternative medications that are less likely to cause hyperkalemia.
Monitoring: Regular monitoring of potassium levels is essential for people taking medications that can raise potassium.

2.3. Dietary Factors

While the kidneys typically regulate potassium levels efficiently, consuming excessive amounts of potassium-rich foods can contribute to hyperkalemia, especially in individuals with kidney disease or those taking certain medications.

2.3.1. Foods High in Potassium

Fruits: Bananas, oranges, avocados, cantaloupe, honeydew melon, dried fruits (raisins, apricots)
Vegetables: Potatoes, sweet potatoes, spinach, tomatoes, beets
Dairy: Milk, yogurt
Other: Chocolate, molasses, salt substitutes (containing potassium chloride)

2.3.2. The Role of Diet in Hyperkalemia

For individuals with healthy kidneys, dietary potassium is usually not a significant concern because the kidneys can efficiently excrete excess potassium. However, people with kidney disease or those taking medications that impair potassium excretion may need to limit their intake of potassium-rich foods to prevent hyperkalemia.

2.3.3. Dietary Recommendations for Managing Potassium Levels

Read Food Labels: Pay attention to the potassium content of foods and beverages.
Limit Portion Sizes: Reduce the amount of potassium-rich foods you consume in one sitting.
Choose Lower-Potassium Alternatives: Opt for fruits and vegetables that are lower in potassium, such as apples, berries, carrots, and green beans.
Preparation Methods: Boiling vegetables can help reduce their potassium content.
Consult a Dietitian: Work with a registered dietitian to create a meal plan that meets your nutritional needs while managing your potassium intake.

3. Less Common Causes of High Potassium

While kidney disease, medications, and dietary factors are the most common causes of hyperkalemia, several less frequent conditions can also lead to elevated potassium levels. These include hormonal disorders, certain medical conditions, and other factors that disrupt the body’s potassium balance.

3.1. Addison’s Disease

Addison’s disease, also known as adrenal insufficiency, is a rare endocrine disorder in which the adrenal glands do not produce enough cortisol and aldosterone. Aldosterone is a hormone that helps regulate sodium and potassium levels in the body.

3.1.1. How Addison’s Disease Affects Potassium Levels

In Addison’s disease, the deficiency of aldosterone leads to reduced sodium retention and decreased potassium excretion by the kidneys. This can result in hyperkalemia, as the kidneys are unable to remove excess potassium from the bloodstream effectively.

3.1.2. Symptoms of Addison’s Disease

In addition to hyperkalemia, symptoms of Addison’s disease may include:

Fatigue: Persistent and worsening fatigue.
Muscle Weakness: Feeling weak or heavy in the muscles.
Weight Loss: Unintentional loss of weight.
Decreased Appetite: Loss of interest in food.
Hyperpigmentation: Darkening of the skin, especially in areas exposed to the sun.
Low Blood Pressure: Dizziness or lightheadedness due to low blood pressure.
Salt Craving: Strong desire for salty foods.

3.1.3. Treatment of Addison’s Disease

Treatment for Addison’s disease typically involves hormone replacement therapy with synthetic corticosteroids, such as hydrocortisone and fludrocortisone. Fludrocortisone helps replace the missing aldosterone and restore the balance of sodium and potassium in the body.

3.2. Rhabdomyolysis

Rhabdomyolysis is a condition in which damaged muscle tissue breaks down rapidly, releasing muscle cell contents into the bloodstream. This can occur due to severe muscle injuries, intense exercise, crush injuries, infections, or certain medications.

3.2.1. How Rhabdomyolysis Affects Potassium Levels

When muscle cells break down, they release large amounts of potassium into the bloodstream. This sudden surge of potassium can overwhelm the kidneys’ ability to remove it, leading to hyperkalemia.

3.2.2. Symptoms of Rhabdomyolysis

Symptoms of rhabdomyolysis may include:

Muscle Pain and Weakness: Severe muscle pain, tenderness, and weakness.
Dark Urine: Tea-colored or dark red urine due to the presence of myoglobin (a muscle protein) in the urine.
Fatigue: Feeling unusually tired or weak.
Muscle Swelling: Swelling and tenderness in the affected muscles.
Nausea and Vomiting: Feeling sick to the stomach.
Irregular Heartbeat: Heart palpitations or an abnormal heart rhythm.

3.2.3. Treatment of Rhabdomyolysis

Treatment for rhabdomyolysis focuses on addressing the underlying cause and preventing complications. This may involve:

Intravenous Fluids: Administering large amounts of intravenous fluids to flush out the kidneys and prevent kidney damage.
Electrolyte Management: Monitoring and correcting electrolyte imbalances, including hyperkalemia.
Dialysis: In severe cases of kidney damage, dialysis may be necessary to remove waste products and excess potassium from the blood.

3.3. Trauma and Burns

Severe trauma, such as crush injuries or extensive burns, can cause cell damage and release potassium into the bloodstream.

3.3.1. How Trauma and Burns Affect Potassium Levels

In trauma and burn injuries, damaged cells release intracellular contents, including potassium, into the circulation. The kidneys may not be able to clear this excess potassium quickly enough, leading to hyperkalemia.

3.3.2. Management of Hyperkalemia in Trauma and Burn Patients

Managing hyperkalemia in trauma and burn patients involves:

Fluid Resuscitation: Administering intravenous fluids to maintain kidney function and promote potassium excretion.
Electrolyte Monitoring: Regularly monitoring potassium levels and other electrolytes.
Potassium-Lowering Medications: Using medications to lower potassium levels, if necessary.
Dialysis: In severe cases, dialysis may be required to remove excess potassium from the blood.

3.4. Other Factors

Other less common factors that can contribute to hyperkalemia include:

Dehydration: Severe dehydration can reduce kidney function and impair potassium excretion.
Metabolic Acidosis: Acidosis, a condition in which the body has too much acid, can cause potassium to shift out of cells and into the bloodstream.
Potassium Supplements: Excessive intake of potassium supplements can lead to hyperkalemia, especially in individuals with kidney disease.
Salt Substitutes: Some salt substitutes contain potassium chloride, which can raise potassium levels if consumed in large amounts.

4. Diagnosing High Potassium

Diagnosing high potassium, or hyperkalemia, involves a combination of medical history, physical examination, and laboratory tests. These steps help healthcare professionals determine the presence and severity of hyperkalemia and identify its underlying cause.

4.1. Medical History and Physical Examination

The diagnostic process typically begins with a thorough review of the patient’s medical history. The healthcare provider will ask about:

Medical Conditions: Any existing kidney problems, heart conditions, diabetes, or other medical issues.
Medications: A complete list of all medications, including prescription drugs, over-the-counter medications, and supplements.
Dietary Habits: Information about the patient’s diet, including the consumption of potassium-rich foods and salt substitutes.
Symptoms: Details about any symptoms the patient is experiencing, such as muscle weakness, fatigue, or heart palpitations.

A physical examination may reveal signs of hyperkalemia or related conditions. This may include:

Vital Signs: Checking blood pressure, heart rate, and respiratory rate.
Muscle Strength: Assessing muscle strength and reflexes.
Heart Auscultation: Listening to the heart for any irregular rhythms or sounds.

4.2. Laboratory Tests

The most important test for diagnosing hyperkalemia is a blood test to measure potassium levels. Additional tests may be performed to evaluate kidney function, hormone levels, and other factors that can contribute to hyperkalemia.

4.2.1. Serum Potassium Test

A serum potassium test measures the amount of potassium in the blood. The normal range for potassium is typically between 3.5 and 5.0 mmol/L. A potassium level above 5.5 mmol/L is considered high, and levels above 6.0 mmol/L can be life-threatening.

4.2.2. Additional Blood Tests

In addition to the serum potassium test, other blood tests may be performed to help determine the cause of hyperkalemia:

Kidney Function Tests: These tests, such as serum creatinine and blood urea nitrogen (BUN), assess how well the kidneys are functioning.
Electrolyte Panel: This panel measures the levels of other electrolytes in the blood, such as sodium, chloride, and bicarbonate.
Complete Blood Count (CBC): This test evaluates the levels of red blood cells, white blood cells, and platelets.
Arterial Blood Gas (ABG): This test measures the levels of oxygen and carbon dioxide in the blood and assesses the body’s acid-base balance.
Hormone Levels: In some cases, hormone levels, such as aldosterone and cortisol, may be measured to evaluate adrenal gland function.

4.2.3. Electrocardiogram (ECG)

An electrocardiogram (ECG) is a non-invasive test that records the electrical activity of the heart. Hyperkalemia can affect the heart’s electrical activity, leading to characteristic changes on the ECG. These changes may include:

Peaked T Waves: Tall, pointed T waves on the ECG.
Prolonged PR Interval: An extended PR interval, which indicates a delay in the conduction of electrical impulses from the atria to the ventricles.
Widened QRS Complex: A broadened QRS complex, which indicates a delay in the conduction of electrical impulses through the ventricles.
Loss of P Waves: Disappearance of P waves, which indicates that the atria are not contracting normally.
Sine Wave Pattern: In severe cases, the ECG may show a sine wave pattern, which is a sign of impending cardiac arrest.

4.3. Differential Diagnosis

When evaluating a patient with suspected hyperkalemia, it is essential to consider other conditions that can cause similar symptoms. This process, known as differential diagnosis, helps healthcare professionals narrow down the possible causes and arrive at an accurate diagnosis.

4.3.1. Conditions That Mimic Hyperkalemia

Pseudohyperkalemia: This condition occurs when potassium levels are falsely elevated in a blood sample due to factors such as:
- Hemolysis: Damage to red blood cells during blood collection, which releases potassium into the sample.
- Thrombocytosis: A high platelet count in the blood sample, which can release potassium during clotting.
- Improper Sample Handling: Allowing the blood sample to sit for too long before testing can lead to potassium leakage from cells.
Other Electrolyte Imbalances: Conditions that cause imbalances in other electrolytes, such as sodium or calcium, can sometimes produce symptoms similar to those of hyperkalemia.
Cardiac Conditions: Certain heart conditions can cause symptoms such as chest pain, palpitations, and irregular heartbeat, which can overlap with the symptoms of hyperkalemia.

5. Managing High Potassium Levels

Managing high potassium levels, or hyperkalemia, involves prompt and effective strategies to lower potassium levels and prevent complications. The specific approach depends on the severity of hyperkalemia and the underlying cause.

5.1. Immediate Treatment for Severe Hyperkalemia

Severe hyperkalemia (potassium levels above 6.0 mmol/L) can be life-threatening and requires immediate medical intervention to stabilize the patient and reduce potassium levels quickly.

5.1.1. Calcium Gluconate

Calcium gluconate is often the first-line treatment for severe hyperkalemia. It does not lower potassium levels directly but helps protect the heart from the effects of high potassium. Calcium gluconate works by stabilizing the heart’s cell membranes, reducing the risk of arrhythmias.

5.1.2. Insulin and Glucose

Insulin promotes the movement of potassium from the bloodstream into cells. To prevent hypoglycemia (low blood sugar), insulin is typically administered with glucose. This combination can rapidly lower potassium levels but has a temporary effect.

5.1.3. Sodium Bicarbonate

Sodium bicarbonate can help lower potassium levels by increasing the pH of the blood, which causes potassium to shift into cells. This treatment is most effective in patients with metabolic acidosis.

5.1.4. Hemodialysis

Hemodialysis is a procedure that removes waste products and excess fluids from the blood when the kidneys are not functioning adequately. It is a highly effective method for rapidly lowering potassium levels in patients with severe hyperkalemia, especially those with kidney failure.

5.2. Medications to Lower Potassium

Several medications can help lower potassium levels in the long term. These medications work through different mechanisms to remove potassium from the body or shift it into cells.

5.2.1. Potassium Binders

Potassium binders are medications that bind to potassium in the digestive tract, preventing it from being absorbed into the bloodstream. The potassium-bound medication is then excreted in the feces, effectively removing potassium from the body.

Sodium Polystyrene Sulfonate (Kayexalate): This is a traditional potassium binder that has been used for many years. It works by exchanging sodium ions for potassium ions in the intestine.
Patiromer (Veltassa): Patiromer is a newer potassium binder that is more effective and better tolerated than sodium polystyrene sulfonate. It works by binding to potassium in the colon.
Sodium Zirconium Cyclosilicate (Lokelma): This is another newer potassium binder that is highly effective and well-tolerated. It works by trapping potassium in the gastrointestinal tract.

5.2.2. Diuretics

Diuretics are medications that increase urine production, helping the kidneys remove excess potassium from the body. However, not all diuretics are suitable for managing hyperkalemia.

Loop Diuretics (e.g., Furosemide): These diuretics can increase potassium excretion by the kidneys. However, they should be used with caution, as they can also cause dehydration and electrolyte imbalances.
Thiazide Diuretics (e.g., Hydrochlorothiazide): These diuretics are less effective at lowering potassium levels than loop diuretics and are generally not used for managing hyperkalemia.
Potassium-Sparing Diuretics (e.g., Spironolactone, Amiloride): These diuretics should be avoided in patients with hyperkalemia, as they can increase potassium levels further.

5.3. Dietary Modifications

Dietary modifications are an essential part of managing hyperkalemia, especially for individuals with kidney disease or those taking medications that affect potassium levels.

5.3.1. Limiting Potassium-Rich Foods

Reducing the intake of foods high in potassium can help prevent hyperkalemia. Common potassium-rich foods to limit include:

Fruits: Bananas, oranges, avocados, cantaloupe, honeydew melon, dried fruits (raisins, apricots)
Vegetables: Potatoes, sweet potatoes, spinach, tomatoes, beets
Dairy: Milk, yogurt
Other: Chocolate, molasses, salt substitutes (containing potassium chloride)

5.3.2. Dietary Recommendations

Read Food Labels: Pay attention to the potassium content of foods and beverages.
Limit Portion Sizes: Reduce the amount of potassium-rich foods you consume in one sitting.
Choose Lower-Potassium Alternatives: Opt for fruits and vegetables that are lower in potassium, such as apples, berries, carrots, and green beans.
Preparation Methods: Boiling vegetables can help reduce their potassium content.
Consult a Dietitian: Work with a registered dietitian to create a meal plan that meets your nutritional needs while managing your potassium intake.

5.4. Monitoring and Follow-Up

Regular monitoring of potassium levels is crucial for managing hyperkalemia effectively. Patients should have their potassium levels checked regularly, especially if they have kidney disease, are taking medications that affect potassium levels, or have a history of hyperkalemia.

5.4.1. Frequency of Monitoring

The frequency of monitoring depends on the individual’s condition and treatment plan. Patients with severe hyperkalemia may need to have their potassium levels checked daily until they are stable. Patients with chronic hyperkalemia may need to have their potassium levels checked weekly or monthly.

5.4.2. Follow-Up Appointments

Regular follow-up appointments with a healthcare provider are essential for managing hyperkalemia. During these appointments, the healthcare provider will review the patient’s medical history, medications, and potassium levels. They may also adjust the treatment plan as needed.

6. Preventing High Potassium

Preventing high potassium, or hyperkalemia, involves adopting strategies to manage risk factors and maintain healthy potassium levels. This is particularly important for individuals with kidney disease, diabetes, heart failure, or those taking medications that can affect potassium levels.

6.1. Managing Risk Factors

Managing underlying health conditions and risk factors is crucial for preventing hyperkalemia.

6.1.1. Kidney Disease Management

Effective management of kidney disease is essential for preventing hyperkalemia. This may involve:

Controlling Blood Pressure: High blood pressure can damage the kidneys and worsen kidney disease.
Managing Diabetes: High blood sugar levels can also damage the kidneys.
Following a Renal Diet: A renal diet is low in sodium, potassium, and phosphorus, which can help protect the kidneys.
Avoiding Nephrotoxic Medications: Certain medications can harm the kidneys and should be avoided if possible.

6.1.2. Medication Management

Careful medication management is essential for preventing medication-induced hyperkalemia. This may involve:

Reviewing Medications: Regularly review your medications with your doctor to identify any drugs that may be contributing to high potassium levels.
Dosage Adjustments: Your doctor may adjust the dosage of certain medications to minimize their impact on potassium levels.
Alternative Medications: If possible, your doctor may prescribe alternative medications that are less likely to cause hyperkalemia.
Monitoring: Regular monitoring of potassium levels is essential for people taking medications that can raise potassium.

6.2. Dietary Strategies

Adopting healthy dietary habits can help prevent hyperkalemia, especially for individuals at risk.

6.2.1. Balanced Diet

A balanced diet that is low in potassium can help prevent hyperkalemia. This may involve:

Limiting Potassium-Rich Foods: Reducing the intake of foods high in potassium, such as bananas, oranges, potatoes, and tomatoes.
Choosing Lower-Potassium Alternatives: Opting for fruits and vegetables that are lower in potassium, such as apples, berries, carrots, and green beans.
Reading Food Labels: Paying attention to the potassium content of foods and beverages.
Limiting Portion Sizes: Reducing the amount of potassium-rich foods you consume in one sitting.

6.2.2. Hydration

Staying well-hydrated is essential for kidney function and potassium balance.

Drink Plenty of Fluids: Aim to drink at least eight glasses of water per day, unless your doctor advises otherwise.
Avoid Dehydration: Be mindful of situations that can lead to dehydration, such as strenuous exercise, hot weather, and illness.

6.3. Regular Check-Ups

Regular check-ups with a healthcare provider are essential for monitoring kidney function and potassium levels.

6.3.1. Monitoring Kidney Function

Regular kidney function tests can help detect early signs of kidney disease and allow for timely intervention.

6.3.2. Potassium Level Monitoring

Regular monitoring of potassium levels can help identify hyperkalemia early, before it becomes severe.

7. When to Seek Medical Attention

Knowing when to seek medical attention for high potassium, or hyperkalemia, is crucial for preventing serious complications. Prompt medical care can help lower potassium levels and stabilize the patient’s condition.

7.1. Symptoms That Warrant Immediate Medical Attention

Certain symptoms may indicate severe hyperkalemia and warrant immediate medical attention. These include:

Severe Muscle Weakness: Sudden or worsening muscle weakness.
Heart Palpitations: Feeling that your heart is skipping beats or fluttering.
Chest Pain: Discomfort or pain in the chest.
Difficulty Breathing: Shortness of breath or troubled breathing.
Fainting or Loss of Consciousness: Passing out or losing awareness.

7.2. Risk Factors That Require Prompt Evaluation

Individuals with certain risk factors should seek prompt medical evaluation if they experience any symptoms of hyperkalemia. These risk factors include:

Kidney Disease: A history of kidney problems or kidney failure.
Diabetes: Poorly controlled diabetes.
Heart Failure: A history of heart failure.
Medications: Taking medications that can raise potassium levels, such as ACE inhibitors, ARBs, or potassium-sparing diuretics.

7.3. Importance of Regular Monitoring

Regular monitoring of potassium levels is essential for individuals at risk of hyperkalemia. If you have any of the risk factors mentioned above, it is crucial to follow your doctor’s recommendations for monitoring and follow-up.

Understanding what is the main cause of high potassium is essential for managing and preventing this condition. Kidney disease, medications, and dietary factors are the most common causes, but other less frequent conditions can also contribute. By managing risk factors, adopting healthy lifestyle habits, and seeking prompt medical attention when needed, you can maintain healthy potassium levels and protect your overall health.

Do you have more questions about potassium levels or other health concerns? Visit WHAT.EDU.VN to ask your questions and receive free answers from our knowledgeable community. Our platform makes it easy to get the information you need, when you need it. Don’t hesitate—your health questions deserve answers. Contact us at 888 Question City Plaza, Seattle, WA 98101, United States, Whatsapp: +1 (206) 555-7890, or visit our website at what.edu.vn for more information.