Metabolic Alkalosis: Causes, Symptoms, Diagnosis, How Does The Body Deal With Metabolic Alkalosis?

What is Metabolic Alkalosis?

A condition when the blood becomes completely alkaline is known as metabolic alkalosis. The normal pH of body is between 7.36-7.44.(1) The body is at the best working capacity when the acid-base balance is towards the alkaline side. Alkalosis occurs when either there are too many alkali-producing bicarbonate ions in the body or there are too few acid-producing hydrogen ions.

There are 4 types of alkalosis, and metabolic alkalosis is one of them.

Metabolic alkalosis is of two types:

  • Chloride-Resistant Alkalosis: This type of metabolic alkalosis occurs when an excess of bicarbonate ions are retained in the body or hydrogen ions shift from blood to cells.
  • Chloride-Responsive Alkalosis: It occurs due to the loss of hydrogen ions after vomiting and dehydration.

What Causes Metabolic Alkalosis?

There are numerous underlying conditions that can lead to metabolic alkalosis.

  1. Loss of Stomach Acid

    It is the most common cause of metabolic alkalosis and occurs due to vomiting or suction through the nasal feeding tube.

    Hydrochloric acid is present in large amounts in gastric juices, its loss leads to an increase in the alkalinity of the blood. Vomiting has different causes and to cure metabolic alkalosis, the cause of vomiting has to be cured.

  2. Excess of Antacids

    In normal cases, antacid does not cause metabolic alkalosis. Those with weak or failing kidney, if use nonabsorbable antacid, it can bring in alkalosis.

  3. Diuretics

    Diuretics are the water pills that are normally prescribed in cases of high blood pressure. It can lead to an increase in urinary acid secretion, which can further lead to an increase in alkalinity in the blood. If metabolic alkalosis shows up, the intake of diuretics should be stopped.

  4. Potassium Deficiency

    Potassium deficiency or hypokalemia leads to the shift of hydrogen ions around the cells to inside the cells. This causes the fluid and the blood to become more alkaline.

  5. Heart, Kidney And Liver Failure

    Failure of the major organs leads to potassium depletion that can lead to metabolic alkalosis.

  6. Genetic Causes

    Inherited diseases such as barter syndrome, Liddle syndrome, Gitelman syndrome, apparent mineralocorticoid excess, and glucocorticoid remediable aldosteronism can cause metabolic alkalosis. However genetic causes stand a very rare chance in this case.

Symptoms of Metabolic Alkalosis

Metabolic alkalosis does not present any symptoms. People suffering from it show signs and symptoms of underlying conditions causing it, which include:

If chronic liver disease is the cause of metabolic alkalosis there can be severe symptoms. In severe cases, metabolic alkalosis can lead to:

How To Diagnose Metabolic Alkalosis?

The doctor takes a medical history and does physical examination. If metabolic alkalosis is doubted, blood and urine test are conducted.

Blood Test

It is done to measure the acidity and alkalinity of blood in the arteries. It is a measure in the scale called pH. In metabolic alkalosis the pH of the blood is high.

The normal pH of blood is between 7.36 and 7.44.(1) If the pH rises above this level, metabolic alkalosis is diagnosed.

Urine Analysis

This test is performed to look for the concentration of chloride and potassium in the urine.

Low potassium concentration might indicate potassium deficiency or laxative overuse.

If chloride is low, it is known as hypochloremia. It is a serious condition and can put a person in shock. It can be due to dehydration. The condition can be treated with a standard saline solution.

How Does The Body Deal With Metabolic Alkalosis?

Lung Compensation

When the food we eat is converted to energy in the cells, the body produces carbon-dioxide.

Carbon dioxide is taken by the blood where it mixes with water to form carbonic acid. This carbonic acid breaks into bicarbonate ions and hydrogen. Bicarbonate ions are alkaline in nature.

These bicarbonate ions can be retained in the blood by changing the rate of breathing. This is called respiratory compensation and the body does it automatically to compensate for alkalosis.

Kidney Compensation

By increasing the excretion of bicarbonate ions, the kidney plays its part to combat alkalosis. It is also an automatic process. Alkalosis can be treated by treating the underlying cause, but it’s important to see a doctor if any symptoms are noticed.