Le chlorine is a electrolyte present in the body (a chemical element capable of carrying an electrical charge in a liquid). It is found in the extracellular fluids of our body, including blood. It is provided by food, and in particular by cooking salt and foods of animal origin.

Chlorine combines with sodium or Potassium to play the following roles:

• regulate the osmotic pressure, or the balance between extracellular and intracellular fluids. It therefore makes it possible to maintain, with sodium, a good state ofhydration

• maintain theacid-base balance

• indirectly promote the transport of CO₂ in the blood

The doctor prescribes an analysis of the blood chlorine level to check the state of hydration of the body and the acid-base balance (pH).

A blood test for chlorine is prescribed by a doctor, at the hospital or during a consultation. The examination consists of a venous blood sample, most of the time at the fold of the elbow. It is not necessary to be fasting to take this blood test.

In both men and women, the normal value of chlorine in the blood is between 100 and 105 mmol / L (millimoles per liter).

An increase in the chlorine level or, conversely, a decrease, may indicate an acid-base imbalance or a hydration problem, which the doctor can interpret. 

When the chlorine concentration is too high, we talk abouthyperchlorémie. This is often associated with Dehydration and can be attributed to many conditions.

Fever, certain metabolic diseases (hyperthyroidism), certain drugs, respiratory alkalosis, etc. may in particular be involved.

On the contrary, a chlorine deficiency, called hypochlorémie, may be encountered in particular in the following cases:

• renal failure

• severe vomiting, diarrhea

• very heavy sweating

• Addison’s disease (adrenal insufficiency)
• respiratory acidosis