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How Long Can A Human Survive Only On Water Alone?

By July 31, 2019November 29th, 2020No Comments

It is normal to be thirsty since it’s the body’s way to survive. Indeed, water is an important nutrient in our body and we need it just like any other being. Water can aid in our digestion and regulate body temperature. It is essential in the disposal of body wastes to be healthy. Furthermore, the brain must acquire water to produce neurotransmitters and hormones.

Water makes up around 65% of the body liquid and it is considered as an abundant molecule. As your body uses the water from outside sources, it will use the water in the fat cells to quench the thirst. This is the same mechanism used by camels to survive for many days under the scorching heat of the sun. They extract the water stored from the body fats. However, the human body does not have this much storage capacity just like the camels do.

After one week of not drinking water, your body will stop to sweat. Then, the body temperature will increase. It will be impossible to facilitate digestion because of the lack of intestinal juices and saliva. Thereafter, blood pressure will decrease because of the reduction of blood volume.

With this feeble body issue, death is possible. Without water, you can disrupt the body’s balance to gain and lose body water. Survival rate can be minimized due to sweating and urinating.

As such, in this article, you will learn the facts about how long can a human survive without water. We will discuss the facts and science behind this myth. Moreover, we will tackle the fad about water diet and why is it getting popular today.

How Long Can a Person Live Without Drinking Water?

In general, you can survive without drinking water for up to 3 days. But there are claims that they have survived 8 to 10 days even a drop of any fluid.

You can stretch the amount of time to survive depending on external factors. Examples of these are the humidity, temperature, and your general health. Athletes who are exercising intensely under the heat of the sun can become dehydrated and die after a few hours only. Meanwhile, there is a prisoner who has reported to survived 18 days without water inside the jail. This has been stretched because he was indoors away from the heat of the sun.

Indeed, one can survive without no fluid indefinitely. This is true if you have consumed enough foods filled with water to replace the fluid lost by your body. The human body does not necessarily need to consume pure water. What it needs are nutrients and electrolytes from the aqueous solution to be absorbed by the body.

According to history, a Chinese sailor named Paoon Lin has survived 133 days without water when his ship sank in 1942. He was left stranded in the open ocean in a raft. Because of the incident, he ran out of supplies and left him without no freshwater for three months. He survived by eating fish and drinking the blood of a shark or seagull. This might be repulsive but the idea made him survive.

Sources of Water

The best source of body fluid is by drinking water. However, you can still get it from eating food such as fruits and vegetables.

To keep your body hydrated, you can also drink beverages like milk or fruit juices. Stay away from drinking alcoholic beverages because this will only lead the body to lose more liquid versus the normal process via urination.

Understanding What is Water Diet

Now that we have understood what will happen to our body after a few days without drinking water, it’s time to discuss water diet. This is the newest fad among many millennials who are concerned about their weight.

You need to understand that there are two types of a diet which are the unhealthy and healthy diet. A good diet can help you adopt a healthy lifestyle. It will make you active, help you eat the good foods, and does not allow you to cut off the important nutrients that your body needs. An unhealthy diet will promise you a quick weight-loss effect but you will only gain the weight back. This is true with the water diet.

This is one of the many trending diets today which is extreme. The idea is you don’t eat any foods at all but only drink water. In some diet variations, they let you drink water for some days and add fruits and vegetables as you begin to shed off some weight. Whereas there are those variations that let you have apples in your water.

This diet is another name for fasting. If you are healthy, a few days of fasting will not affect you. But this is still a bad idea to lose weight. You will starve and you will have to eat according to your normal eating patterns. With this, you will only gain back the weight that you have lost.


Cold Water Diet 

This idea is not a diet in actuality since there is no restriction on what you eat. The only thing that you have to do is to drink cold water. When you drink cold water, the body will heat to the normal body temperature of around 98.6 degrees. As such, the colder the drink is, the more calories are burned by your body. Moreover, drinking more cold water will make you feel full for a longer period of time which makes you less likely to eat. Finally, water can flush out the toxins from your body.

How Do You Water Fast? 

There are no scientific rules on how to begin water fasting. However, you have to take note that there are groups of people who are not recommended to fast without consulting a doctor. This includes patients with diabetes, gout, eating disorders, kidney disease, elderly, pregnant women, and children.

If you have never tried water fasting in the past, it will be best to try three to four days to prepare your body. Try surviving these number of days without eating any food. Moreover, you can also start eating smaller portions only or by fasting for a day.

Pros and Cons of Water Fasting or Water Diet

Fasting is a method of restricting the intake of food which has been practiced since time immemorial. In water fasting, it restricts everything except for the intake of water. Today, this idea is becoming popular to lose some weight.

Meanwhile, research provides that water fasting or water diet can actually provide the body with some benefits. However, there is a limited resource or study with regards to water fasting. Remember that this diet comes with various health risks and it is not recommended for everyone. Here are its top benefits:

Promotes Autophagy

Going into water diet can help promote autophagy. This is a natural body process where old cells are broken down and used once again. Several studies conclude that autophagy can help the body fight against heart diseases, Alzheimer’s, and even cancer.

This is because autophagy can avoid further damage to the cells which is a risk factor among cancer patients. With this, it can aid in preventing the cancer cells from growing. However, further studies are needed to be conducted to support water fasting’s benefits and autophagy.

It May Help Lower Blood Pressure

Experts have claimed that people who have high blood pressure can undergo long water fasting in order to lower their blood pressure. It is said that as long as the fasting is medically supervised, then their blood pressure will surely lower down to healthy levels.

One study has shown that 56 out of 68 persons saw the levels of their blood pressure lower down to 120/80 mmHg. Significantly, the average drop was 7mmHg for diastolic or lower value and 20 mmHg for the systolic or upper value.

In another study, 157 out of 174 persons who have undergone the said fasting for 10 to 11 days have dropped their blood pressure lower than 140/90 mmHg. And in addition, the average decrease of the systolic blood pressure was 37 mmHg.

Although studies have shown great results, there still are no human researches that examine the connection between the short-term water fasts, which lasts for 24-72 hours, and the blood pressure.

It May Develop Insulin and Leptin Sensitivity

Studies have shown that through water fasting, the body becomes more sensitive to insulin and leptin. These two are the important hormones that affect the metabolism of the body. The insulin stores the nutrients that came from the bloodstream while the leptin makes the body feel full. Thus, the said hormones will become more effective depending on how sensitive they are.

For instance, if one’s body is more efficient at decreasing the levels of blood sugar, then the body is insulin sensitive, and on the other hand, if one’s body is more efficient in processing hunger signals, then it is leptin sensitive. In addition, being leptin sensitive means that a person has a lower risk of being obese.

It Lessens the Risk of Some Chronic Diseases

Studies have shown that people who have undergone water fasting may have a lower risk of diabetes, cancer, heart disease, and other chronic diseases.

One instance is where 30 healthy adults have decreased their levels of cholesterol and triglycerides after undergoing the said fasting for 24 hours. Indeed, cholesterol and triglycerides are two of the main factors of heart disease.

There were also some animal studies that have proved that the heart could be protected against the damage from the free radicals, and the genes that help cancer cells grow could be suppressed just by undertaking water fasting. Free radicals are known to play some major role in many chronic diseases due to the damage it could cause in some parts of cells.

Before making recommendations, always remember that there is still not enough evidence to show the good effects of water fasting in humans.

Threats and Risks of Water Fasting

Water fasting does have some health benefits, but having too much may cause some health risks. Here are some of the risks and dangers of undergoing water fasting.

You May Shed the Wrong Weight

Studies have shown that water fasting restricts the calories, thus undergoing the said fasting for 24-72 hours could help a person lose up to 2 pounds of weight. Unfortunately, most of the weight a person would lose may come from carbs, water, and even the muscle mass.

Become Dehydrated

Not all of the water in a person’s body came from their drinks, roughly 20 to 30% came from the food they eat. Thus, there’s still a possibility of dehydration when person water fast. A dehydrated person may feel dizzy, headaches, nausea, constipation, low productivity, and low blood pressure.

If a person drinks a constant amount of water without eating any foods, then their bodies won’t be getting enough water. Therefore, a person must drink more than the usual amount.

You May Grieve From Orthostatic Hypotension

Orthostatic hypotension is the dropping of the blood pressure that usually happens when a person suddenly stands up, it then leaves the person lightheaded, dizzy, and might be at the risk of fainting. This is usually common for people who fast.

It is strongly advised that a person should avoid driving or operating any heavy machinery if he or she happens to have orthostatic hypotension.

Also, if this phenomenon happens then the person should consider not stopping the fasting.

Water Fasting May Aggravate Some Medical Illnesses

Although water fasting may seem no harm, it is still not recommended to some people without any proper medical supervision. Such examples of medical conditions are gout, diabetes, chronic kidney disease, eating disorder, and heartburn.

People who suffer from gout are not advised to water fast because it would increase their uric acid production which is a risk factor for gout attacks. Diabetics are also not allowed because fasting could increase the risk of side effects in the 2 types of diabetes. While persons who have chronic kidney diseases may cause further damage to their kidneys if they water fast.

People may also experience heartburn because the stomach produces more acids due to not having food to digest. Moreover, water fasting could encourage eating disorders like bulimia to teenagers as per the studies have shown. 

The Hazard Of Dehydration

Since the body constantly loses water, a glass of liquid is not enough to replenish the body. A person loses water when sweating, peeing, and even exhaling. An adult could even lose up to 1.5 liters of water per hour in under extreme conditions. And if the water that’s lost was not replaced, then the volume of one’s body fluid could decrease rapidly and could even cause the dropping of blood volume.

Having a minimal volume of blood circulating the body could be fatal for a person because the blood pressure decreases to lethal levels. The temperatures of the body would also increase especially when a person stops sweating.

Thus, if symptoms occur, better to administer to the nearest hospital because if the body loses water more than 10% of one’s weight it could be very dangerous and could even lead to death. is a replacement water and air filter company located in the United States. The views and opinions contained herein are solely those of the original author and do not represent Eco Blue Life or its affiliates. This article was originally published on  
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