Sodium

What is sodium?

Sodium is a mineral that you ingest through your daily diet. Meat, fish, and grain products naturally contain sodium, but the largest source is table salt. Table salt consists of sodium chloride, a compound of sodium and chlorine.

In the body, sodium performs several essential tasks. It helps maintain the acid-base balance, regulates fluid balance, and is necessary for the normal functioning of the nerves. Additionally, it plays a role in the uptake of glucose and certain amino acids into the cells.

The concentration of sodium in your blood is the result of a delicate interplay between the heart, the brain, the kidneys, and the adrenal glands. The kidneys regulate how much sodium is excreted, and that process is influenced by hormones produced by the adrenal glands and the pituitary gland in the brain.

Why is sodium measured?

A sodium level in the blood shows whether the balance between salt and fluid is disturbed. This is valuable information, because even small shifts in that balance can have noticeable consequences for how you feel and how your organs function.

Doctors have sodium levels measured when heart or kidney disease is suspected, but also when someone has symptoms consistent with a disturbed fluid balance. Regular monitoring of sodium levels is also useful when using certain medications, such as water pills (diuretics).

Most adults consume more salt through their diet than is desirable. The recommendation is to aim for a maximum of six grams of salt per day. This corresponds to approximately 2.4 grams of sodium. This guideline is primarily aimed at keeping blood pressure within a healthy range.

What do abnormal values ​​mean?

Sodium levels that are too low

A sodium level that is too low, also known as hyponatremia, can have various causes. Persistent vomiting or diarrhea can lead to a loss of sodium through the gastrointestinal tract. The sodium balance can also be disrupted in cases of burns, peritonitis, or irritable bowel syndrome.

Furthermore, certain medications, such as diuretics, can lower sodium levels. Conditions such as diabetes, Addison's disease, kidney failure, and SIADH syndrome (a condition in which too much antidiuretic hormone is produced) can also be associated with reduced levels.

High sodium levels

An elevated sodium level, or hypernatremia, occurs when too little sodium is excreted or when there is a fluid deficit in the body. This can occur in heart failure, liver cirrhosis, and kidney failure, where sodium excretion is reduced.

Other causes include excessive fluid loss, intravenous sodium administration, or hormonal disorders such as Conn's syndrome or Cushing's disease. A simple but important cause is also insufficient fluid intake.

Sodium, salt, and your health

Prolonged high salt intake increases blood pressure. High blood pressure is in itself a risk factor for more serious conditions, such as heart failure, stroke, and kidney damage. Reducing salt in the diet is therefore one of the most effective lifestyle measures to lower blood pressure.

A true sodium deficiency due to diet is rare. Most people actually consume too much. In exceptional cases, such as during extreme exertion with excessive sweating or with prolonged gastrointestinal complaints, an acute deficiency can occur.

Chronic kidney failure develops slowly and often causes few symptoms in the early stages. Only when kidney function is severely impaired and waste products accumulate in the blood can symptoms occur such as reduced appetite, nausea, fatigue, itching, and loss of muscle strength. Measuring sodium is part of a broader assessment of kidney function.

When is it advisable to have your sodium measured?

It can be useful to have your sodium level determined if you have symptoms indicating a disturbed fluid balance, such as extreme thirst, infrequent urination, swelling in the legs, or unexplained fatigue. Periodic monitoring is also valuable in the case of known conditions such as heart or kidney problems.

Do you take medication that affects fluid balance, such as diuretics or certain antidepressants? Then it is especially wise to monitor your sodium level. A single blood test quickly provides clarity regarding your salt-fluid balance and forms a useful part of a broader blood test.