How long does water intoxication last

Drinking water is essential to keeping the body healthy and functioning properly. However, there's such a thing as drinking too much water too fast, aka water intoxication.

Water intoxication occurs when you drink so much water that the kidneys can't eliminate it fast enough, so it begins to dilute electrolytes — primarily sodium — in the blood. 

Although it's rare, water intoxication can lead to death if not treated immediately.

Here are the symptoms of water intoxication and how it is generally treated.

How much is too much water?

Water intoxication is a dangerous and severe condition because blood sodium levels drop rapidly, causing neurologic changes like hallucinations and confusion.

Important: Drinking too much water can lead to hyponatremia, which occurs when blood sodium levels drop below 134 mEq/L. There are some instances where hyponatremia poses no immediate threat to a person's health. However, the rapid drop of sodium levels from water intoxication can cause neurological symptoms and needs immediate treatment. 

Adults need to drink about 2.7 to 3.7 liters of fluids a day, which will come from water, food, and other beverages.

Water intoxication may occur from drinking more than three to four liters of water over a short period, like one or two hours, says Lewis Nelson, MD, chair of emergency medicine at the Rutgers New Jersey Medical School.

Note: Water intoxication can develop from excessively drinking fluids other than water, such as beer — a condition called beer potomania, Nelson says.

No specific amount of fluid is considered unsafe, however, and the risk of water intoxication will vary depending on the frequency of intake, age, sex, and overall health.

Symptoms of water intoxication

Water intoxication is primarily a neurological syndrome, says Nelson. Too much water may make the brain swell and disrupt normal functioning.

The early symptoms of water intoxication may include the following:

• Headaches
• Confusion
• Nausea
• Vomiting
• Forgetfulness

If not treated immediately, it may lead to other symptoms, such as:

• Slurred speech
• Weakness
• Hallucinations
• Muscle cramps
• Impaired brain functioning
• Seizures
• Coma

Water intoxication tends to occur among adults who run marathons, do military training, and have mental health conditions like psychogenic polydipsia (aka compulsive water drinking) or schizophrenia. However, it can also develop in babies.

Infants younger than six months are not allowed to have water because they have small bellies and their kidneys are not yet developed. If they are given water or their baby formula is over-diluted, they may experience water intoxication. Symptoms include vomiting, irritability, weakness, and seizures.

How to treat water intoxication

Water intoxication can be lethal, and it must be treated immediately.

"Patients with water intoxication have a medical emergency and should be brought to the hospital for emergent medical care. We would typically need to stop their seizures, infuse concentrated sodium-containing solution, and support their breathing," says Nelson.

You will need intravenous electrolyte solutions and other medications to restore normal blood sodium concentration. The mortality rate for patients with water intoxication is about 7.1%.

Insider's takeaway

Water intoxication occurs when you drink too much water to the point that you dilute the sodium concentration in your blood. It can cause neurological symptoms such as weakness, seizures, or impaired brain functioning.

To treat water intoxication, you would need intravenous fluids to increase sodium levels in the blood.

"If you suspect someone has severe water intoxication with features such as obtundation [or a reduced level of alertness], seizures, coma, or others, call 911 for emergency assistance," says Dennis Moledina, MD, Yale Medicine nephrologist and assistant professor at the Yale School of Medicine.

Brain cells are particularly susceptible to overhydration and to low sodium levels in the blood. When overhydration occurs slowly and is mild or moderate, brain cells have time to adapt, so only mild symptoms (if any) like distractibility and lethargy may ensue. When overhydration occurs quickly, vomiting and trouble with balance develop. If overhydration worsens, confusion, seizures, or coma may develop.

When overhydration occurs and blood volume is normal, the excess water usually moves into the cells, and tissue swelling (edema) does not occur. When excess blood volume occurs, fluid can accumulate in the lungs and lower legs.

Overhydration, sometimes also called water intoxication, is a condition induced when too much water is consumed over a short period leading to dilution of the body’s salt and electrolyte levels. This produces a homeostatic disruption in functions of various aspects of your body, in particular your cognition, muscles, urinary tract, and bladder. Immediately reducing fluid intake will correct the problem in most cases, though if symptoms persist you should see a doctor.

Although quite uncommon, overhydration can be related to several conditions. A study published in the British Journal of General Medicine by Angus H N Whitfield found that high endurance athletes or those who engage in intense physical activity are often most at risk for this condition as they are likely to over-hydrate in an effort to refresh themselves during exercise. Additionally, underlying organic and non-organic health conditions such as Diabetes Insipidus, Syndrome of inappropriate antidiuretic hormone secretion (SIADH), Psychogenic polydipsia, or even schizophrenia can also cause inadvertent overhydration.

Water intoxication is not a major daily concern for an average person as they are more often dehydrated than overhydrated. Here though is a list of nine symptoms of drinking too much water.

• Your urine is very clear.
• You are suffering from a persistent headache and nausea.
• You wake up several times throughout the night to urinate.
• You drink water even if you are not thirsty.
• You have unsteady or weak muscles.
• You are continuously weary and exhausted.
• You are feeling perplexed or disoriented.
• You have swelling feet, hands, or lips.
• You have low blood sugar.

1. Your Urine Is Very Clear.

The color of your urine is one of the most obvious indicators of the body’s hydration levels. When urine has a completely clear or transparent color, this indicates your body’s waste excretions are diluted and it is likely that you have drunk too much water. The color of urine is ideally between clear and that of light straw and honey according to a Cleveland clinic article entitled “What The Color of Your Pee Says About You” by Dr. Petar Bajic.

If your urine is consistently very clear, you are probably drinking too much water throughout the day. Reducing your fluid intake until it is light yellow will correct the problem in most cases. See a doctor if it does not. This chart provides a guide to assessing your urine color to determine your hydration status.

2. You Are Suffering from a Persistent Headache and Nausea.

If you suffer from persistent headaches and nausea at the same time that you are drinking high amounts of fluids, the issue may be overhydration. These symptoms are some of the most commonly reported in cases of both mild and severe water intoxication and subsequent hyponatremia according to an article on overhydration in the Merck Manual of Diagnosis and Therapy by Dr. James L. Lewis. If one is drinking too much water, the excretory system cannot process the excess fluid quickly enough, which leads to a homeostatic disruption throughout the entire body, leading to headaches and nausea.

Reducing your fluid intake to see if it corrects the problem. If headaches become intractable and are associated with nausea and vomiting, this may be a sign of impending neuronal damage and individuals should seek medical help, according to Dr. Ananya Mandal, a physician and researcher in West Bengal, India.

3. You Wake Up Several Times throughout the Night to Urinate.

If you wake up several times throughout the night to urinate, you may be overhydrating. Many adults can sleep the full night without waking up with a need to urinate. It is also normal to wake up once during the night to urinate, especially as you get older or after having children.

The European Urology Journal reported in 2012 that 55% of men and 60% of women aged 50 wake at least once in the night to urinate, with an additional 20% waking up at least twice. This issue, referred to as nocturia, is a sign of biological dysregulation. In addition to overhydration, it may be a sign of other physiological issues or disorders.

If urination becomes too common, especially after reducing fluid intake, it is important to talk to your doctor about both daytime and nighttime bathroom use frequency. Your doctor can help to determine whether overhydration or a different medical issue is the cause.

4. You Drink Water Even If You Are Not Thirsty.

If you drink water even when you are not thirsty, this could be a sign of overhydrating. The feeling of thirst is your body’s natural signal to drink, so if you are not feeling thirsty you should not force it. Lack of thirst is your body communicating that it is already properly hydrated and does not need more fluid at that time.

Adult men should drink about 3.7 liters (125 fluid ounces) of water a day and adult women should drink about 2.7 liters (90 fluid ounces) daily, according to studies by both the Mayo Clinic and the US National Academies of Sciences, Engineering, and Medicine. While factors such as exercise, climate, age, and lifestyle will impact your adequate intake of fluids, if you find yourself drinking more water than this while not feeling thirsty, you should reduce your fluid intake and speak with your doctor.

5. You Have Unsteady or Weak Muscles.

Overhydration can lead to water intoxication, a serious condition that affects all areas of the body. If you have unsteady or weak muscles, this is an early sign of water intoxication. When we drink too much water, the excess fluid gets stored in our muscles, which leads to weakness and unsteadiness. People report that the unsteadiness is similar to the unsteadiness one might feel after alcohol consumption. This unsteadiness and weakness can eventually lead to muscle cramps and spasms, according to Dr. Ananya Mandal, a physician and researcher in West Bengal, India.

To treat the overhydration, simply stop drinking water until you feel the strength return to your muscles. Seek medical attention if this does not bring your muscles back to normal condition.

6. You Are Continuously Weary and Exhausted.

A more subtle indication that you are overhydrating daily is if you are continuously weary and exhausted. Overhydration dilutes the body of some of its important nutrients and minerals, which can lead to you feeling tired, according to a study on the physiology, psychology, and pathology of overhydration from Wayne State University’s Division of Kinesiology, Health and Sport Studies.

If you are hyperhydrated, you may notice yourself having less stamina or becoming tired more easily. If you have been drinking a lot of water and notice reduced energy, the culprit may be excess fluid in your bloodstream. Reduce your fluid intake while maintaining healthy food intake and exercise to see if you return to a normal energy state. If not, speak with your doctor to see if other conditions are causing you to be tired.

7. You Are Feeling Perplexed or Disoriented.

Brain fog is another sign that you may be drinking too much water. If you are feeling perplexed or disoriented after hydrating, it may be a sign that you have had far too much water and may be close to developing water intoxication. People describe the early stages of water intoxication as feeling similar to alcohol intoxication.

If you are drinking more than the recommended amount of water (3.7 liters per day for men or 2.7 liters for women as a generic baseline but adjusted for your personal circumstances) and notice that you are easily distracted, perplexed, or disoriented, you should immediately reduce your fluid intake. You should seek medical attention immediately according to Dr. James Lewis in his article on overhydration published in the Merck Manual of Diagnosis and Therapy.

8. You Have Swelling Feet, Hands, or Lips.

If you have swelling in your face and extremities, you may be overhydrated. This swelling is referred to as edema and is the consequence of excess fluid in the tissues, according to Dr. Andrea Thompson from the University of Michigan. Edema can occur when one drinks too much water and plasma volume expands. The ankles, feet, face, and hands are typically the most noticeable areas to swell, but the entire body can experience swelling as well. A sensation of bloating in the stomach may also be common with edema.

This video shows an example of performing a self-test for edema based on swelling.

If you are overhydrated and notice swelling in your extremities, it should clear away as you reduce fluid intake levels and your body water levels return to normal. However, edema alone is not enough evidence to determine if you are overhydrated, as there are many other causes of fluid retention in the body. The issue is often the presence of too much salt in your diet or some other underlying medical condition. Talk with your doctor if you have persistent swelling so they may help determine the cause.

9. Low Blood Sugar

When you are overhydrated, you may experience low blood sugar as the excess water in the body dilutes the blood’s sugar (glucose) content. Low blood sugar may cause you to experience tremors, pallor, anxiety, increased heart rate, sweating, and palpitations, according to the Center for Disease Control and Prevention. The CDC reports that “severe low blood sugar is below 54 mg/dL” and that at levels this low, people often feel weak and/or faint. This is a serious symptom of potential overhydration, so reduce your fluid intake and seek medical intervention immediately if you notice a drastic change in your overall awareness or strength.

How Much Water Is Too Much in a Day?

How much water is too much in a day is determined by several factors and is specific to each individual person. The Institute of Medicine’s Dietary Reference Intake (DRI) does provide general guidance for the ideal water amount per day for different age groups. For men and women aged between 19 and 50, the average recommended intake is anywhere between 2.7 and 3.7 liters per day of total fluids. According to the DRI, this “includes approximately 2.2 L (≈ 9 cups) as total beverages, including drinking water” and 3.7 L/day of total water, which “includes approximately 3.0 L (≈ 13 cups) as total beverages, including drinking water” (2006).

The typical rule of “eight glasses per day” usually equals out to about 1.5-2.0 L of water, meaning it actually might be beneficial to drink beyond eight, though this depends on how much fluid you are receiving from other beverages and food. However, when wondering "can you drink too much water?" one needs to remember that each person’s water needs are different, especially depending on their exercise, local climate, age, and health conditions.

To account for body weight and exercise, physical therapist and clinical supervisor Jennifer Stone suggests two other very basic formulas, displayed below, for determining how much water to drink per day.

• If not exercising: Body Weight (pounds) / 2 = intake in fluid ounces. Multiply by 29.6 for number in milliliters.
• If exercising: Bodyweight (pounds) / 2 + Water Lost = intake in fluid ounces. Multiply by 29.6 for number in milliliters. To determine the water lost portion of the formula, weigh yourself before and after exercising. For each pound (0.45 kg) lost, drink around 16-20 oz (0.5-0.6 liters) of water.

If you feel adverse effects after increasing your daily water consumption you may be drinking too much in a day for your particular needs.

What Are the Dangers and Risks of Drinking Too Much Water?

The main danger and risk of drinking excessive water is water intoxication, although this is rare. During water toxicity, excess water migrates to sites in the body with increased solute concentration due to osmosis. This site is often inside the cell, and during water intoxication, cells begin to swell.

The danger increases when neurons in the central nervous system begin to swell as this increases pressure inside the enclosed cranium which leads to symptoms of confusion, lethargy, headache, drowsiness, and under certain circumstances seizures or coma. Water intoxication can also lead to muscle spasms, organ failure, and even death. Although water intoxication is dangerous and potentially life-threatening, it is exceedingly rare and dehydration is a much more common condition that is equally as dangerous if not addressed.