This content originally appeared on diaTribe. Republished with permission.

By April Hopcroft

Key takeaways: 

Hydration is important, but drinking too much water when exercising without consuming enough salt (an electrolyte) can put you at risk for low sodium levels.
People with diabetes have a higher risk of electrolyte disorders, especially if they also have heart failure or kidney disease.
You can prevent low sodium after exercise by balancing water intake with electrolytes, which are found in sports drinks, coconut water, tomato juice, and other vegetable juices, as well as many foods.

During exercise, especially something rigorous, staying hydrated is top of mind for many people. However, drinking too much water during or after exercise without consuming enough sodium can cause a condition known as hyponatremia – in this case, exercise-associated hyponatremia.

Hyponatremia is a common disorder, occurring in up to one-third of hospitalized patients. Runners and other endurance athletes who lose salt through sweat and consume too much water without enough sodium may develop hyponatremia.

What is hyponatremia?

Hyponatremia describes a lower than normal amount of sodium or salt in the blood. Sodium is essential to proper functioning of your body – specifically, for balancing fluids and nerve function, said Dr. Raj Dasgupta, a board-certified physician specializing in internal medicine, pulmonology, and critical care.

When sodium in your bloodstream is diluted by too much water – as can happen if you’re drinking a lot during exercise – water enters your cells and causes them to swell. This can lead to many problems, including seizures or a coma caused by swelling of brain cells.

What causes hyponatremia?

Hyponatremia can be caused by drinking too much water, taking certain medications (like diuretics), or having kidney problems that cause the body to hold onto too much water. Balancing fluid and blood sodium levels is often difficult in the advanced stages of chronic kidney disease.

Dasgupta added that hormonal issues that affect fluid balance, particularly those related to antidiuretic hormone, can also cause hyponatremia.

What are the symptoms?

Mild hyponatremia may not have any symptoms. Moderate to severe symptoms of hyponatremia include:

Nausea and vomiting
Headache
Confusion
Fatigue or low energy
Dizziness
Muscle weakness, cramps, or spasms (twitching)
Low blood pressure
Restlessness or irritability

More serious symptoms include:

Altered mental status (severe confusion)
Hallucinations
Seizures
Coma

Contact your healthcare provider if you experience any mild to moderate symptoms.

Is hyponatremia connected to diabetes?

Anyone can develop hyponatremia, but certain groups of people are more at risk. Electrolyte disorders generally are common in people with diabetes, especially older individuals and those with heart disease or chronic kidney disease. However, diabetes does not directly cause hyponatremia.

Exercise-associated hyponatremia is usually temporary and easily treated. However, people who have health conditions that cause their body to retain too much water are at the highest risk for chronic low sodium levels including:

Heart failure
Cirrhosis, a severe form of liver disease
Syndrome of inappropriate antidiuretic hormone

Additionally, certain medications can increase the risk of hyponatremia, including diuretics (often called water pills), antidepressants, and antipsychotic drugs.

For instance, the diuretic hydrochlorothiazide is known to increase the risk of low sodium, Dasgupta said. Diuretics help reduce fluid buildup in the body by helping the kidneys to produce more urine. They are commonly used to treat conditions like high blood pressure, heart failure, and kidney disease.

Of course, drinking too much water also puts you at risk for hyponatremia. This includes people who use the drug ecstasy since it can make you feel thirsty and cause you to drink too much.

How should I prevent hyponatremia?

To prevent hyponatremia after exercise, Dasgupta advised making sure you balance water intake with enough food or drinks containing electrolytes.

Sports drinks like Gatorade can be a good source of electrolytes, though these drinks often contain large amounts of added sugar. Look for the no sugar alternatives of these drinks like Gatorade G Zero. Natural sources of electrolytes include coconut water and many foods. Salty foods like pickles contain especially large amounts of sodium and other electrolytes.

“Be careful not to drink too much water quickly,” Dasgupta said. “And pay attention to your hydration needs, especially if you’re on medication or have health conditions.”

How is hyponatremia treated?

Hyponatremia is treated based on how serious it is and what caused it. Changes in fluid intake and diet can often help resolve mild cases. In serious cases, medications or IV sodium may be needed.

Ultimately, Dasgupta said it’s important to address any underlying issues that might be contributing to low sodium levels.

The bottom line

It’s always a good idea to stay hydrated during and after exercise to avoid hyponatremia, especially if you’re in a hot environment that makes you sweat more. If you’re undertaking strenuous exercise and sweating a lot, it’s especially important to balance water intake with salt (an electrolyte).

While diabetes doesn’t directly cause hyponatremia, it’s commonly experienced by people with diabetes and other chronic conditions like heart and kidney disease.

To balance out your salt levels, consume sports drinks or coconut water, but avoid any drink with large amounts of added sugar. Many stores also sell salt tablets, powder, or chewable gummies. Many cases of hyponatremia are resolved with fluid replacement, but extreme cases might need immediate medical attention.

Learn more about managing diabetes here:

6 ‘Exercise Snacks’ to Fit Into Your Day
Diabetes and High Potassium Levels
5 Supplements People With Diabetes Should Avoid