Hyponatremia is as real and serious as dehydration. Unfortunately it occurs a lot in sports due to out of context information. This article helps to illuminate the reader to recognize the signs early on and several of the potential situations that can lead to Hyponatremia and how to effectively deal with them.

Mild Hyponatremia can also occur in daily life, especially during the metabolic reset and adaptation phases of OFM. 

Hyponatremia: Because of all the talk about Hydration most athletes know to consume plenty of water during exercise, however, while most are aware of electrolytes, most do not understand how balance electrolyte intake with fluid intake for a given situation. Remember, Hydration is very dynamic! In many cases the electrolyte intake is non-existent or insufficient compared to the water intake and this can lead to Hyponatremia.

Preventing Hyponatremia is the best strategy, but with the plethora of well-intened but out of context information out there it is no wonder Hyponatremia occurs frequently. Recognizing the symptoms early is key to preventing potentially catastrophic problems. 

Here are some signs:

  • At home or work mild Hyponatremia manifests itself as mental fog, lack of energy and general sluggishness.
  • During physical activity, training or competition, one of the first signs is nausea and a sloshy stomach as the water does not have the osmotic potential to pass through into the blood from the stomach and gut. Nausea is often mistaken as sickness and the athlete consumes even more water thinking this will thin things out and make it go away, only making the situation worse. Recognize this early, correct it and generally you will be fine within an hour.
  • Another symptom is your sweat rate will decrease and with it so will your performance.
  • A third symptom is you will become mentally foggy and dizzy.
  • In certain cases you will develop sausage fingers and toes and even overall swelling (edema) where you have sodium but it is low in relation to water. This is very common in mountain ultra marathons due to renal issues arising out of the combination of electrolyte imbalances and an overload of myoglobin and protein from damaged tissues due to the impact of running. CPK is a marker for this, however, since you are not going to get your blood drawn and tested for CPK during training or a competition you need to be aware and recognize the signs early on.


What to do: 

  • Prevention is the best option. Be aware of your hydration status. Take in adequate water &electrolytes to REPLACE what you are losing through sweat and urination. 
  • In most cases take in some sodium-based electrolytes or a Hypertonic drink and back off the water until your sweat rate returns and/or you urinate. 
  • Another practical way to do this is to drink V8 or Tomato Juice. If it is hot use the spicy version for extra sodium. 
  • In some cases an IV of Hypertonic Saline Solution is warranted by a trained professional.
  • Often eating food will correct hyponatremia so stop and eat.
  • If you are running an ultra or doing a multi-day run or adventure race be sure to keep your feet in good shape to prevent myoglobin and protein release which will cause renal issues. 
  • In cold weather hydrate minimally and only after you have lost roughly 1% of your body weight.