Treatment of Hyponatremia

Fatal hyponatremia is becoming a serious problem especially for serious athletes who are involved in intensive training. It has common in marathon runners and military recruits, as well as, anyone else in intensive training.

Fatal hyponatremia in athletes is rare, but it has claimed the lives of marathon runners and military recruits, and should therefore be brought to the attention of sports/health professionals. However, it is clear from epidemiological (population) data that hyponatremia associated with prolonged exercise is quite rare. It is very important to keep the risk of ‘overhydration’ in perspective. For example, one study of ‘higher risk’ athletes who developed symptomatic hyponatremia were participating in distance running events of 42 km and triathlons lasting 9–12 h. In these events, symptomatic hyponatremia still only occurred in 0.1–4% of the participants.

Sourced from:

Luckily, severe hyponatremia is quite rare but that does little to eliminate the seriousness of the ailment. It manifests in two types; acute and severe intoxication.

Acute and Chronic Water Intoxication

In acute water intoxication, blood sodium levels drop under 130 mmol/L within 48 hours, and in chronic water intoxication in more than 48 hours.

Sourced from:

Chronic water intoxication involves extremely low levels of sodium; under 130mmol/ L in more than 48 hours. Studies have shown that intake of excess water is a primary factor in hyponatremia.

Excessive drinking is a key risk factor for hyponatremia, and this risk can be reduced by making certain that fluid intake does not exceed sweat loss and by ingesting sodium containing beverages or foods to help replace the sodium lost in sweat. As a safeguard, athletes can include sodium containing sports drinks for exercise lasting more than 1-2 hours, especially during activity in the heat when sweat losses are greatest. Sports drinks are also beneficial by means of supplying carbohydrates when muscle fuel stores may run low during intense training or competition lasting more than 1-2 hours.

It is advised that athletes should intake sports drinks with sodium for exercises lasting more than two hours. Sodium is an important electrolyte in the human body especially because the mineral is an important component of neurotransmission.



The electrolyte sodium is very important in hydration and electrolyte status. The Latin word for sodium is natrium, thus the term hyponatremia for the condition where the sodium concentration in body fluids is dangerously low. The sodium concentration in extra-cellular fluid is the ratio of weight of sodium ions to weight of water. So, if I have too much water, I can just add more sodium, right? Well, it depends on where you are with respect to normal sodium content in the body. If you have too little sodium, then adding more will help you return to normal. An example many runners have experienced would be low sodium with adequate water, leading to puffiness in the hands and wrists. Taking in more sodium will correct the situation and the puffiness will go down. But if you have the right amount of sodium, adding a lot more is not good. Excess sodium can increase thirst and prompt more drinking, which is bad if you already have too much water on board (excess weight). Thus, the safest course is to drink to maintain body weight (or be a little down), and take sodium supplementation conservatively. A deficiency of water or sodium can be corrected within minutes, but correcting excesses of either one can take hours.

Sourced from:

Many athletes however, may prefer to drink only water, and should be aware of misleading advice to ‘always drink as much as you can’. The amount of water an athlete should drink depends on their volume of sweat and the sodium concentration of their sweat, both of which can vary depending on aerobic fitness, exercise intensity and ambient temperature.

The problem is that most athletes prefer to take a lot of water during and after their intensive exercise, a situation that may lead to overhydration. The following are the short and long-term effects of hyponatremia on the body;

Short-Term Effects on the Body Organs

  • Brain swelling (cerebral edema)
  • Lung swelling (pulmonary edema)
  • Muscle breakdown (rhabdomyolysis)

Long-Term Complications

An episode of a severe hyponatremia may leave a person with a permanent brain damage resulting in:

  • Mental retardation
  • Diabetes insipidus
  • Persistent vegetative state
  • Hearing loss
  • Cerebral palsy
  • Gait abnormality

Severe hyponatremia has been linked to problems such as cerebral palsy, hearing loss, and even diabetes insipidus. The following are some preventive and treatment steps that athletes can take to monitor their health;

  • Weight in and weight out – make it a habit to weight yourself before pursuing any exhaustive activity. The target is to match the amount of weight loss due to sweat with an equivalent volume of fluid right after the exercise. The rule of thumb for these events is to drink at least 20 ounces of fluids, preferably with electrolytes, within several hours after each training session and, most importantly, after the event.
  • Keep drinking tabs – it is important that we keep track of our fluid intake, regardless if it is during training or during the event. Keeping track will help us understand our drinking patterns, which, in turn, will help us, determine the correct amount of fluid we should take. One important fact to note, sports drinks count as water and should be taken into consideration when tracking fluid intake.
  • Eat salt – not literally of course, but a steady intake of salty food while training will keep your sodium levels in check and prevent water retention.
  • Rest – beginners should take advantage of any rest stop available. Especially in high temperatures, endurance athletes should take a rest and let cool their body down.
  • Sip It – Never gulp down any fluid during or after an exercise, always take fast, short sips to slowly cool down the body and prevent accidental water intoxication. Gulping in too much at a time will prevent the body from absorbing the fluid and will result in excessive water in our system.

Sourced from: