Diarrhea Dangers and Serious Complications with Severe Diarrhea

Most of us do not associate diarrhea with any serious consequences. We often experience diarrhea that may last for a few days and resolves a short while thereafter. Apart from the frequent trips to the toilet and other symptoms of diarrheal illnesses like abdominal cramps, diarrhea is often thought of as a minor ailment. However, this is not always true. In fact diarrhea can be deadly and is one of the leading causes of infant death across the globe.

Serious Complications with Diarrhea

Complications can arise with every disease. It simply means that the effects of a disease can cause disturbances of other organs or systems that were not the main target of the disease. Some complications may be minor and resolve on its own once the disease is treated. Other complications may be severe and  continue even after the disease has been cured. These ongoing complications may therefore also require medical treatment.

While some disease itself can cause death, others may only lead to death due to the complications that arise as a result of the disease. Diarrhea is a symptom of many diseases, particularly gastrointestinal diseases. While diarrhea itself may not kill, the complications can be deadly. It is therefore important to seek medical attention for diarrhea, particularly if it is severe or persistent.

Read more on can diarrhea kill?


Dehydration is the leading complication of diarrhea. Copious amounts of fluid and electrolytes is lost with watery diarrhea. This can be further compounded by vomiting and profuse perspiration due to a fever. Depending on the severity of the diarrhea (with or without vomiting), several liters of water loss within a 24 hour period.

Electrolytes are lost along with the water. These salts are used for various biochemical processes in every cells and organ. Dehydration affects the functioning of almost every organ in the body. Eventually this can compromise vital systems like the heart, lungs and brain. It eventually leads to death.

Read more on dehydration.


Diarrheal illnesses affect nutrition in various ways. Firstly, food intake is reduced during diarrhea and some people stop eating altogether, opting instead for fluids only. Secondly, movement through the gut is rapidly increased reducing the ability of the gut to digest and absorb nutrients.

As a result malnutrition can set it very quickly and this in turn affects biochemical processes throughout the body. Over time this can also lead to severe secondary illnesses and even death. However, dehydration often causes death in diarrheal illnesses before malnutrition.

Weight Loss

Unintentional weight loss occurs within hours and days of severe diarrhea. Most of this weight loss is due to the loss of water. However, fat and muscle loss occurs thereafter if the diarrhea persists. This is in part due to reduced nutritional intake and other metabolic effects associated with diarrhea.

It may also arise with the cause of the diarrhea. Significant weight loss can affect functioning of various organs and systems, including the endocrine system, and this can result in serious complications. The reduced body weight may also impact people using medication for other conditions which in turn can cause serious side effects.


The loss of fluid and electrolytes affects the cardiovascular system in various ways. Blood volume is reduced due to the water loss and vital electrolytes needed for normal heart functioning are depleted. As a result the amount of blood pumped by the heart (cardiac output), heart rhythm and rate are adversely effected.

Eventually the ability to distribute oxygen throughout the body is severely compromised. Heart failure or even sudden cardiac arrest may arise and this leads to death. In addition, arrhythmias and the loss of blood volume may lead to the formation of clots which could result in heart attacks and strokes.


Disturbances in water and electrolyte levels due to diarrhea also impacts on kidney functioning. The kidneys play a vital role in balancing the water and electrolyte levels, regulating blood pressure and expelling wastes from the body. Acute kidney failure can arise with severe diarrhea.

As a result the heart function is compromised and waste products build up in the bloodstream. Urination ceases altogether in many instances. Acute kidney failure can lead to death if not properly treated and managed. People with chronic kidney disease (CKD) may be at a greater risk in diarrheal illnesses.

Read more on signs of kidney failure.


Brain tissue is among the most sensitive in the body. Even short term changes in blood oxygen and glucose levels can affect quickly affect brain function. Fluid loss can also cause a reduction in cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. This may further compromise brain function.

Nerves are also affected as electrolytes are required for the transmission of nerve impulses. Therefore the activity of various organs may also be compromised. Changes in the cardiovascular system due to to diarrhea can also increase the risk of strokes.


Diarrhea often occurs due to gastrointestinal infections. However, it may also arise for various other non-infectious causes. Diarrhea can disturb the normal intestinal flora (good bowel bacteria) which in turn increases the risk of bowel infections which may in turn worsen the diarrhea further.

Furthermore the effects of diarrhea, such as malnutrition and dehydration, may weaken the immune system. This leaves the body prone to various infections, not only in the gastrointestinal tract. Some of these infectious can be serious. Without restoration of the immune defenses, even minor infections can be deadly.


The wide ranging effects of dehydration and the other complications of diarrhea can increase the risk of accidents. Slower reflexes, poor coordination and balance, muscle weakness and impaired senses may arise with diarrhea. All of these factors can contribute to accidents.

It may range from falls to the impaired operation of vehicles and equipment. Injuries may vary depending on the situation but can sometimes even lead to life-threatening consequences. While these accidents are a result of the complications of diarrhea, it nevertheless has to be considered as a possible deadly complication of diarrhea.

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