What is hyponatremia?
Hyponatremia is a condition that happens when sodium levels in your blood are too low. Sodium is an important electrolyte. It helps your body manage the amount of water your cells take in. As sodium levels decrease, water levels increase. This can cause swelling in the cells. Hyponatremia is not a disease. It's a symptom of a problem that needs medical attention.
Causes of hyponatremia
Hyponatremia happens when your blood sodium levels fall below 135 mEq/L.This can happen for a variety of reasons. Certain medications can change the way your kidneys work. Medical conditions that affect your heart, liver, kidneys or endocrine system can cause water retention. They can also affect your body's ability to produce hormones that balance your sodium and water levels. The following medical conditions, drugs and lifestyle habits can also cause hyponatremia:
- Kidney disease
- Pain medication
- Cirrhosis of the liver
- Congestive heart failure
- Drinking too much water
- Adrenal gland insufficiency
- Chronic and severe vomiting
- Sweating during endurance activities
- Syndrome of inappropriate anti-diuretic hormone (SIADH)
Risk factors for hyponatremia
Even seemingly healthy people can develop hyponatremia. This condition can affect up to 30% of ultra-endurance athletes. When these athletes train and participate in competitions, they may lose large amounts of sodium as they sweat. If they also drink water to hydrate their bodies, they risk diluting the sodium levels in their bloodstream to very low levels.
Other risk factors for hyponatremia include:
Location: People who live in warm climates have an increased risk of hyponatremia because they're more likely to sweat and drink water when it's hot out.
Burns: Burn victims have an increased risk of hyponatremia during the first few hours after the incident because of damage to their skin's absorbency.
Diet: Those who eat a low-sodium diet also have an increased risk of hyponatremia because they don't eat large amounts of sodium.
Age: Older people are more likely to take prescription drugs or have a chronic medical condition that causes hyponatremia.
Gender: Female endurance athletes are more likely to develop hyponatremia than their male counterparts.
Symptoms of hyponatremia
Symptoms of hyponatremia don't always appear suddenly. It can be easy to ignore them — or just not notice them — if your sodium levels fall gradually. Many of the symptoms are also appear due to other conditions. That can also make them easy to miss. These symptoms include:
- Muscle cramps or spasms
Diagnosis of hyponatremia
A diagnosis of hyponatremia starts with a thorough medical exam. When doctors suspect hyponatremia, they do blood and urine tests. These check the level of sodium in your blood. This also helps them pinpoint the cause of the condition. If the level of sodium in your blood is low but high in the urine, that can mean you're losing sodium through elimination. If sodium levels are low in both your blood and your urine, you may be taking in too much water.
Treatments for hyponatremia
Immediate treatment for hyponatremia is to raise the level of sodium in your blood. This may be as simple as cutting back on your fluid intake. Your doctor might change the dosage of medications like diuretics. Severe cases may require a hospital stay. That way, you can receive a sodium solution directly into your veins, so it works fast. You may also need treatment for underlying conditions that are causing your hyponatremia.
Recovery from hyponatremia
Recovery from hyponatremia depends on what caused the problem. Most people return to their regular activities as soon as their sodium levels return to normal. Your doctor may want you to make lifestyle changes. These can reduce your chances of getting this condition in the future.