Sodium (Na)

Why this test?

To determine the degree of hyponatremia and hypernatremia, which often occurs with dehydration, edema and other diseases?

To diagnose pathology of the brain, lungs, liver, heart, kidneys, thyroid gland, adrenal glands, which is a consequence or result of sodium deficiency or excess?

To control the effectiveness of the treatment of patients with a violation of the composition of electrolytes, for example, when taking diuretics.In what cases is it prescribed?

In what cases is it prescribed?

During a standard laboratory examination as part of a biochemical analysis of blood in most people (along with a group of other electrolytes: chlorine, potassium, magnesium).

With non-specific complaints to control the results of treatment of arterial hypertension, heart failure, kidney and/or liver diseases.
If dehydration is suspected.

With symptoms of hyponatremia (weakness, lethargy, confusion) and hypernatremia (thirst, decreased urine output, convulsions).

With a sharp drop in the level of sodium, a person can feel weak and tired, in some cases there is confusion of consciousness up to a comatose state.

With a slower decrease in sodium concentration, there may be no symptoms at all, so its level is still checked even in the absence of symptoms.

Test information

Sodium is a vital trace element, which is necessary for the transmission of impulses in the nervous system and muscle contractions. The sodium ion interacts with other electrolytes (potassium, chlorine, carbonate anion) and regulates the body's water-salt balance.

Together, they ensure the normal functioning of nerve endings - the transmission of weak electrical impulses and, as a result, muscle contraction. Sodium is present in all body fluids and tissues, but its highest concentration is in blood and extracellular fluid. The level of extracellular sodium is controlled by the kidneys. For humans, the source of sodium is table salt. Most people get their daily allowance of this element. Gastrin, secretin, cholecystokinin, and prostaglandins affect the absorption of sodium in the intestines. The body takes part of the exogenous sodium for its needs, and the rest is excreted by the kidneys, maintaining the electrolyte concentration in a very narrow range. Mechanisms of sodium maintenance: production of hormones that increase or decrease sodium loss in the urine (natriuretic peptide and aldosterone), production of a hormone that prevents fluid loss in the urine (antidiuretic hormone), thirst control (antidiuretic hormone). When the level of sodium in the blood changes, the amount of fluid in the tissues of the body also changes.

Most often, this leads to dehydration or swelling (especially of the legs). Of all electrolytes, sodium is the most abundant in the human body. It plays a major role in the distribution of fluid between the extracellular and intracellular spaces. In addition, it participates in the transmission of nerve impulses and contraction of the heart muscle.

Without a certain amount of sodium, the body is not able to function, so it is so important that its level is stable and does not undergo significant fluctuations. Sodium is excreted by the kidneys, and its concentration is regulated by the hormone aldosterone, synthesized in the adrenal glands. Other factors that maintain sodium at a constant level are the activity of the enzyme carbonic anhydrase, the action of hormones from the anterior lobe of the pituitary gland, the secretion of the enzyme renin, ADH, and vasopressin.