Does Drinking Water Lower Sodium Levels

What is sodium

Sodium is an essential mineral that is needed for our body to function properly. You may see it referred to as an electrolyte, which is a mineral with an electric charge. We need approximately 500mg of sodium every day in our diet. However, too much sodium can have a negative impact on our health, leading to high blood pressure, heart disease, and stroke.¹ Sodium levels in our body are tied to how much water we consume. In this article, we will explore how sodium is used in our body and how water affects it. 

Benefits of sodium in our health

We need sodium in our body to perform vital functions. It helps to: 

  • Conduct electrical signals in our nerves 
  • Contract and relax muscles. 
  • Maintenance and balance of water and other vital minerals 
  • Transportation of nutrients and other essential compounds²

Sources of sodium

Sodium occurs in very few food sources naturally. Celery, milk, and beetroot contain sodium, otherwise, the mineral is added to packaged and premade food. Sodium adds flavour and helps stabilise other elements in food.³ 

Sodium is often confused with salt. Salt refers to a crystalline compound that contains sodium. It comes in different forms, such as: 

  • Table salt- or sodium chloride, is the most widely used salt. 
  • Kosher salt- coarsely grained salt prepared in the traditional Kosher method. 
  • Sea salt- made by evaporating seawater. May also contain trace elements (potassium, zinc, or iron) which have added health benefits 
  • Himalayan pink salt- from the mountain range in Pakistan. Its colour comes from tiny amounts of iron oxide.¹

According to the CDC, in America, sodium is mainly consumed in: 

  • Bread and pastries
  • Pizza 
  • Pasta 
  • Burgers 
  • Eggs 
  • Soups 
  • Tacos, burritos 
  • Savoury snacks (popcorn, crisps) 
  • Cold meats⁴

Water and sodium levels

Effects of water in sodium levels

Drinking plenty of water is often encouraged as part of a healthy lifestyle, however, drinking too much water can be dangerous. If we consume too much water than our kidneys can excrete, it can lead to a phenomenon known as water intoxication. This is a rare condition and is more common in individuals with mental health issues.⁵ 

Too much water in our body can dilute the concentration of sodium in the blood, causing a condition called hyponatremia. Symptoms of hyponatremia can present after drinking 3 to 4 litres of water, such as confusion, drowsiness, or even a coma.⁶ Hyponatremia occurring over a short period of time is particularly dangerous as it can lead to cerebral oedema, or swelling of the brain.⁷

Conversely, if we drink too little water, this increases the concentration of sodium in the blood, causing hypernatremia. This can cause you to feel irritable and agitated for no reason, progressing to tiredness, drowsiness, and a coma. This is less common than hyponatremia, but is considered to be more dangerous.⁸

Effects of high sodium level

As sodium levels increase, more water is retained by the body to help dilute it. This increases the fluid not only surrounding the cells in our body, but also the volume of blood. With more blood to pump around, this puts more stress on the heart and more pressure on the blood vessels. This can lead to you developing high blood pressure, stroke, or even a heart attack. If the blood volume is raised for too long, it can lead to your heart not being able to meet the demands of your body, leading to heart failure.¹

If you have very high levels of sodium in your body, you will breathe at a faster rate than normal, feel restless, or have difficulty sleeping. You will also be dehydrated as there is less water available for your body to use. If you become severely dehydrated, it can lead to shock and other serious complications.⁹

How to measure sodium level

Sodium levels in your body can be measured in one of two ways: by your blood or urine. Sodium levels are not checked alone, and the levels of other electrolytes are measured alongside. This gives a better overall assessment of the body’s function. The test is performed by taking a small amount of blood from your vein, usually in the arm. It is painless, but if there is pain, it will be a small amount and will disappear quickly after.¹⁰

To test sodium levels in your urine, a small sample of urine is needed to be tested in the lab. Sometimes, you may be required to provide your urine over 24 hours. Before the test, you will be asked to stop certain medications that may affect test results, such as corticosteroids, diuretics, or nonsteroidal anti-inflammatory drugs(e.g. ibuprofen).¹¹

Recommended water intake 

Ensuring that we drink enough water every day is vital in helping the body perform optimally. Water helps carry nutrients and oxygen to cells, flush bacteria out in urine, and prevent constipation.¹² The Eatwell Guide recommends that we should drink 6 to 8 glasses of fluid per day. This includes:

  • Water - the best liquid in aiding hydration, however, it can be boring to drink. For those who have trouble drinking enough water, try sparkling water, or adding flavour with lemon or lime. 
  • Milk - Semi-skimmed, 1% fat, or skimmed milk contains important vitamins and minerals like calcium. 
  • Tea and coffee - are fine to drink, however, caffeine does cause you to produce urine faster.
  • Sports drinks - these are helpful during sports to boost energy, however, they are high in sugar and calories. Water is healthier and a better way of replacing fluid lost during exercise.¹³

Other ways to balance sodium levels

Here are a few tips to help reduce the levels of sodium in your diet: 

  • Read nutrition labels - compare food before buying to see what contains less sodium.
  • Prepare your own food at home - packaged sauces, mixes, and microwave food contain higher levels of sodium than homemade food.
  • Add flavour without salt - try limiting the amount of salt in your cooking. There are alternative seasoning mixes and herbs that do not contain salt.
  • Buy fresh food - processed food contains higher levels of sodium, 
  • Rinse canned food - this helps wash off any excess sodium.
  • Choose unsalted snacks.
  • Reduce your portion size - if there is less food on your plate, then you will consume less sodium.⁴


Water and sodium play important roles in our health. Drinking enough water is important for balancing the levels of electrolytes in our bodies. However, too much of a good thing can be harmful, and drinking fluid excessively to the level of water intoxication can lead to serious health problems. This is fortunately a rare occurrence and should not discourage you from trying to achieve optimal hydration levels.  


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  2. Strazzullo P, Leclercq C. Sodium. Adv Nutr. 2014 Mar;5(2):188.
  3. Sodium sources: Where does all that sodium come from? [Internet]. [cited 2022 Oct 29]. Available from:
  4. Center for Food Safety, Nutrition A. Sodium in Your Diet [Internet]. U.S. Food and Drug Administration. FDA; [cited 2022 Oct 29]. Available from:
  5. Farrell DJ, Bower L. Fatal water intoxication. J Clin Pathol. 2003 Oct;56(10):803–4.
  6. Jose CJ, Perez-Cruet J. Incidence and morbidity of self-induced water intoxication in state mental hospital patients. Am J Psychiatry. 1979 Feb;136(2):221–2.
  7. Joo MA, Kim EY. Hyponatremia caused by excessive intake of water as a form of child abuse. Annals of Pediatric Endocrinology & Metabolism. 2013 Jun;18(2):95.
  8. Adrogué HJ, Madias NE. Hypernatremia. N Engl J Med. 2000 May 18;342(20):1493–9.
  9. Sonani B, Naganathan S, Al-Dhahir MA. Hypernatremia. In: StatPearls [Internet]. StatPearls Publishing; 2022.
  10. Sodium blood test [Internet]. Mount Sinai Health System. [cited 2022 Nov 3]. Available from:
  11. Sodium urine test [Internet]. Mount Sinai Health System. [cited 2022 Nov 3]. Available from:
  12. How much water should you drink? [Internet]. Harvard Health. 2022 [cited 2022 Nov 3]. Available from:
  13. Water, drinks and your health [Internet]. [cited 2022 Nov 3]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Lauren Young

Doctor of Medicine - MD, Medical University of Sofia, Bulgaria

Lauren is a newly qualified doctor, who recently returned to the UK to pursue a career as a GP. Her passions lie in public health, medical education and health advocacy. An avid reader, Lauren has found great joy in combining her love of medicine and the written word in writing health articles for Klarity.

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