What is Keshan Disease? Causes, Symptoms, and Treatment

December 27, 2025 •

6 min read

First discovered in China in 1935, Keshan disease is a serious form of endemic cardiomyopathy with historical mortality rates over 98% in some outbreaks, primarily linked to severe dietary selenium deficiency and viral co-factors. However, widespread selenium supplementation has dramatically reduced its incidence, shifting the primary clinical concern from acute fatalities to managing chronic and latent cases.

Quick Summary

An endemic cardiomyopathy, Keshan disease damages the heart muscle, leading to heart failure and arrhythmia. It is triggered by the interplay of severe selenium deficiency and a viral infection, specifically certain strains of coxsackievirus.

Key Points

Endemic Cardiomyopathy: Keshan disease is an endemic heart muscle disorder primarily affecting people in specific, low-selenium regions of China.
Multi-Factorial Cause: The disease results from a combination of severe dietary selenium deficiency, a viral trigger (often coxsackievirus), and potential genetic factors.
Fatal without Intervention: Historically, Keshan disease carried a very high mortality rate, particularly in its acute form, but this has been drastically reduced by prevention programs.
Four Clinical Types: It is classified into four clinical presentations: acute, subacute, chronic, and latent, each with varying severity and onset.
Preventable through Supplementation: Widespread public health programs involving selenium supplementation, such as adding it to table salt, have been highly effective in preventing Keshan disease.
Selenium's Protective Role: The trace mineral selenium is crucial for antioxidant enzymes that protect the heart; its deficiency compromises this protection and makes the heart vulnerable to viral damage.
Diagnosis by Location: Diagnosis often relies on clinical symptoms combined with a patient's history of residing in a low-selenium endemic area.

What is Keshan Disease?

Keshan disease is a form of congestive cardiomyopathy characterized by multifocal necrosis and fibrosis of the heart muscle, leading to an enlarged heart and heart failure. It is named after Keshan County in Heilongjiang province, China, where it was first identified. The condition's geographic distribution closely aligns with a belt of low-selenium soil stretching from northeast to southwest China, where locally grown food is the primary nutrient source.

Endemic and Socioeconomic Factors

Historically and even today, the disease is most prevalent in poor, rural, and mountainous regions where residents rely on locally grown crops. This dependency makes local populations susceptible to nutritional deficiencies tied to the soil's composition. While most cases have been documented in China, similar conditions have been reported in other regions with low soil selenium, including parts of Russia, Korea, and Japan. Keshan disease primarily affects children, especially between ages two and five, and women of childbearing age.

The Complex Etiology: Selenium, Viruses, and Genetics

For decades, the exact cause of Keshan disease was a medical mystery. Today, it is understood as a multifactorial disease involving a complex interaction between environmental and genetic factors.

The Role of Selenium Deficiency

Selenium is a crucial trace mineral, essential for the function of selenoproteins, including glutathione peroxidases (GPx). GPx enzymes are powerful antioxidants that protect the heart muscle from oxidative damage. In regions with selenium-deficient soil, local crops and, consequently, the diets of residents have low selenium content. This severe deficiency impairs GPx activity, making the heart more vulnerable to damage.

Viral Co-factor

Research suggests that selenium deficiency is not the sole cause and that a secondary trigger is often a viral infection, most notably a mutated strain of coxsackievirus B3 (CVB3). Studies have shown that when a host is selenium-deficient, the virus can mutate into a more virulent strain that specifically targets the heart muscle. Evidence of viral RNA has been found in the hearts of patients with Keshan disease, supporting this theory.

Genetic Predisposition

Certain genetic factors and polymorphisms have also been linked to an increased susceptibility to Keshan disease. For example, some individuals may have variations in genes that affect selenoprotein function or other cardiac processes, increasing their risk when combined with selenium deficiency and viral exposure.

The Clinical Spectrum of Keshan Disease

Keshan disease presents in four clinical types, which vary based on the onset and severity of symptoms.

Acute Keshan Disease:
- Rapid onset, often severe, and historically associated with high mortality rates.
- Symptoms include cardiogenic shock, severe arrhythmia, heart failure, dizziness, and dyspnea.
- More common in children in winter and women of childbearing age.
Subacute Keshan Disease:
- Slower onset than the acute form.
- Combines features of cardiogenic shock and congestive heart failure.
- Characterized by significant heart dilation.
- Most commonly affects young children (2–5 years old).
Chronic Keshan Disease:
- Characterized by insidious onset and slow progression, with symptoms of chronic heart failure.
- Leads to dilated heart chambers, thinning of heart walls, and extensive myocardial fibrosis.
Latent Keshan Disease:
- Presents with few or minor cardiac abnormalities and compensated heart function.
- Often detected incidentally through ECG showing abnormalities like ventricular extrasystole or bundle branch blocks.

Diagnosis and Management

Accurate diagnosis of Keshan disease requires considering clinical symptoms in the context of residence in an endemic area and low selenium status.

Diagnostic Indicators

Serum or Blood Selenium Levels: Testing reveals significantly low concentrations of selenium.
Glutathione Peroxidase (GPx) Activity: Blood tests show reduced activity of this selenium-dependent enzyme.
Electrocardiogram (ECG): Shows characteristic abnormalities, particularly useful for diagnosing latent cases.
Echocardiography: Detects cardiac dilation and wall motion abnormalities, especially in chronic cases.
Family History: A family history of the disease is a significant risk indicator, suggesting a genetic component.

Treatment Protocols

The cornerstone of treatment is selenium supplementation, typically using sodium selenite tablets, which have proven highly effective in reducing mortality. However, treatment must be carefully monitored by a doctor to avoid selenium toxicity, which can cause symptoms like hair loss and fatigue. Standard heart failure medications, such as diuretics and ACE inhibitors, are also used to manage symptoms. In severe cases, cardiac surgery or transplants may be necessary.

Keshan Disease vs. Idiopathic Dilated Cardiomyopathy

Keshan disease can be difficult to distinguish from Idiopathic Dilated Cardiomyopathy (IDCM), which also causes heart dilation and dysfunction. However, key differences exist, as shown in the table below.


Feature	Keshan Disease	Idiopathic Dilated Cardiomyopathy (IDCM)
Primary Cause	Multifactorial: Selenium deficiency and viral infection (e.g., Coxsackievirus B)	Exact cause is unknown (idiopathic)
Geographic Distribution	Endemic to specific low-selenium regions, historically China	Worldwide distribution; not tied to specific geographic regions
Family History	Often clusters within families and has a genetic component	Can have a familial component, but not to the extent or with the same endemic pattern
Socioeconomic Link	Primarily affects impoverished, rural populations reliant on local crops	Not linked to socioeconomic status
Key Diagnostic Marker	Low blood selenium levels and reduced GPx activity	Diagnosis by exclusion after other causes ruled out
Treatment Focus	Primarily selenium supplementation and heart failure management	Symptom management with standard heart failure medications

Prevention Strategies

The dramatic reduction in Keshan disease incidence in China over recent decades demonstrates that the condition is largely preventable. The primary strategy has been public health programs that introduce selenium supplementation to endemic areas, including adding sodium selenite to table salt.

Individuals living in at-risk areas can take preventive measures through dietary and lifestyle changes:

Dietary Modifications: Consuming selenium-rich foods can help, though this depends on the selenium content of the soil where the food was grown. Good dietary sources include seafood, meat, grains, and nuts.
Supplements: For those in deficient regions, a daily selenium supplement is recommended.
Regular Monitoring: Regular medical check-ups and ECG monitoring are crucial for detecting and managing latent cases before they progress.

Conclusion

Keshan disease is a fascinating and sobering example of how a trace mineral deficiency can interact with viral and genetic factors to cause a debilitating and potentially fatal heart condition. While modern prevention efforts through large-scale selenium supplementation have drastically reduced its impact, it remains a public health concern in historical endemic areas. Continued surveillance, education, and access to proper nutrition are essential to ensure this rare but significant cardiomyopathy is managed effectively. The story of Keshan disease highlights the critical importance of micronutrients in maintaining human health. For more detailed information on the broader effects of selenium deficiency on health, you can consult sources like the NIH Office of Dietary Supplements' fact sheet on selenium.

Disclaimer: The information in this article is for educational purposes only and is not a substitute for professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any health condition.

What is the history of Keshan disease?

First documented in 1935 in China's Heilongjiang province, Keshan disease was later found to be endemic in a wide belt of low-selenium soil stretching across the country. Its prevalence and severity peaked in the 1960s and 1970s before large-scale selenium supplementation programs were implemented, which significantly reduced its incidence.

Who is most susceptible to Keshan disease?

Keshan disease most commonly affects young children aged 2–5 and women of childbearing age, particularly those living in impoverished, rural, mountainous areas with selenium-deficient soil. People in these regions often have diets based solely on locally grown food, increasing their risk of severe selenium deficiency.

Is Keshan disease still a problem today?

While the incidence of acute and subacute cases has dramatically decreased due to supplementation efforts, chronic and latent forms of Keshan disease still persist in historically endemic areas. It remains a public health issue requiring ongoing monitoring and management.

How does selenium deficiency lead to heart damage?

Selenium deficiency reduces the activity of key antioxidant enzymes like glutathione peroxidase (GPx), which protect heart cells from oxidative damage. This makes the heart muscle more susceptible to injury, particularly when a viral infection like coxsackievirus is also present, leading to the necrosis and fibrosis characteristic of the disease.

Can Keshan disease be cured?

There is no absolute cure, but early treatment with selenium supplementation has proven highly effective in reversing some of the damage and reducing mortality rates. Management also involves standard heart failure therapy. The prognosis is significantly better with timely diagnosis and intervention.

What are the different types of Keshan disease?

There are four recognized clinical types: acute (rapid onset, severe symptoms), subacute (slower onset, heart dilation), chronic (slow progression, chronic heart failure), and latent (few or no symptoms, detected by ECG abnormalities).

What other factors contribute to Keshan disease besides selenium deficiency?

Beyond severe selenium deficiency, co-factors can include infection with a mutated coxsackievirus B, genetic predispositions affecting selenium-related genes, and other nutritional deficiencies like vitamin E. The interplay of these factors determines the disease's manifestation.

Frequently Asked Questions

Keshan disease is an endemic cardiomyopathy, a condition that damages the heart muscle, primarily caused by a combination of severe dietary selenium deficiency and viral infection. It leads to heart enlargement and failure and was historically found in certain regions of China.

The primary cause is a severe deficiency of the trace mineral selenium, which occurs in regions with low-selenium soil. A co-factor is often an infection with a specific strain of coxsackievirus, which can become more virulent in a selenium-deficient host. Genetic predisposition also plays a role.

Keshan disease is endemic to a belt-like region of rural, low-selenium soil across China, although similar cases have been reported in other countries with similar soil conditions, such as Japan and North Korea. It is most prevalent in poor, rural populations who rely on local food sources.

Symptoms vary depending on the type (acute, subacute, chronic, latent) but can include dizziness, nausea, shortness of breath, fatigue, palpitations, and symptoms of heart failure or cardiogenic shock. In latent cases, symptoms may be minimal.

Diagnosis is based on clinical symptoms, residence in an endemic area, and confirmation of low blood selenium levels and reduced activity of selenium-dependent enzymes. Abnormalities seen on an electrocardiogram (ECG) and echocardiography are also key diagnostic indicators.

The main treatment is selenium supplementation, usually through oral tablets of sodium selenite, to correct the deficiency. Standard medical therapies for heart failure, such as diuretics and ACE inhibitors, are also used to manage cardiac symptoms.

Yes, large-scale public health programs providing selenium supplements, often by fortifying table salt or crops, have been highly successful in reducing the disease's incidence. Dietary changes to include selenium-rich foods are also recommended for at-risk populations.