The body functions best when its pH is slightly alkaline. Metabolic alkalosis occurs when the pH level becomes too alkaline. It can happen when diarrhea, vomiting, or excessive urination lead to an imbalance of electrolytes in the blood.

Electrolytes are minerals and salts such as chloride and potassium that play a vital role in many bodily processes. Dehydration, conditions that affect the kidneys, and certain medications can lead to electrolyte imbalances.

Read on to learn more about the causes, symptoms, and treatment of metabolic alkalosis.

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Metabolic alkalosis is a condition that occurs when the body’s chemistry becomes too alkaline.

A pH level measures how acidic or alkaline something is. The pH scale runs from 0 to 14, with a pH of below 7 being acidic and a pH above 7 being alkaline.

The body has an overall pH level and functions best when the blood is slightly alkaline, at pH 7.35 to 7.45. However, to maintain this level, the body must continuously balance substances that could disrupt it, such as acids, electrolytes, and gases in the blood.

If the body produces too much acid or does not remove enough acid, it develops acidosis. If the body produces too much alkali or does not remove enough alkali, it develops alkalosis.

Doctors divide metabolic alkalosis into two categories. It is possible to experience both forms at the same time.

Chloride-responsive alkalosis

This type of alkalosis occurs due to the loss of chloride in the urine or gastrointestinal tract.

Chloride is an electrolyte that increases the blood’s acidity. Losing too much chloride can result in higher alkalinity. Doctors call this subtype “chloride responsive” because they can treat it by replacing the lost chloride.

Chloride-resistant alkalosis

This type occurs when there are high levels of bicarbonate, which is alkaline, in the blood.

To an extent, the body can compensate for an imbalanced pH through breathing.

To maintain a healthy pH, the body uses a process known as the bicarbonate buffer system. This system exchanges carbon dioxide and bicarbonate between the blood and lungs. While bicarbonate makes the blood more alkaline, carbon dioxide makes it more acidic.

If the body becomes too alkaline, it increases carbon dioxide in the lungs through hypoventilation, or decreased breathing. The body can also increase or decrease bicarbonate levels in the blood by increasing or decreasing breathing rate.

The kidneys work to increase the elimination of bicarbonate through urine. Together, these two systems help restore the body’s acid-alkaline balance.

Metabolic alkalosis does not have symptoms in itself, but the electrolyte imbalance or condition causing it might. For example, a person may develop metabolic alkalosis due to a loss of fluids from vomiting, diarrhea, or excessive urination.

In more severe cases, metabolic alkalosis causes the body to bind more calcium, creating low calcium levels. This can lead to:

Various conditions can cause metabolic alkalosis, including:

  • Potassium deficiency: A person can develop hypokalemia, or low potassium levels, if they do not consume enough potassium in their diet. It can also occur if a person has difficulty absorbing potassium.
  • Conn’s syndrome: This adrenal disease leads to hypertension, high sodium, low potassium, and metabolic alkalosis.
  • Stomach acid loss: Gastric juices contain hydrochloric acid. If the body loses excessive amounts of stomach acid, the blood’s alkalinity can rise. Vomiting, chloride-rich diarrhea, or suction through a nose-feeding tube can lead to stomach acid loss.
  • Diuretics: These medications increase urine production and promote sodium loss. Examples include thiazide diuretics, such as hydrochlorothiazide, and loop diuretics, such as furosemide.
  • Drug overdose: Some drugs contain sodium bicarbonate and calcium carbonate, both of which can disrupt the electrolyte balance in the body if a person takes too much. Sodium bicarbonate, or baking soda, is a substance some people use as a home remedy for heartburn. Similarly, calcium carbonate is the main ingredient in many antacids.
  • Reduced effective arterial blood volume: If someone has a weak heart or liver cirrhosis, it can affect how well the body removes bicarbonate from the blood.
  • Heart, kidney, or liver failure: Failure of a major organ can also affect how well the body eliminates carbon dioxide and balances electrolytes.
  • Genetic causes: Some people inherit a tendency to develop metabolic alkalosis. For example, people with cystic fibrosis may lose fluids, resulting in alkalosis. More rarely, Gitelman syndrome and Bartter’s syndrome can affect how the kidneys function.

Doctors can diagnose metabolic alkalosis by testing blood pH.

They may diagnose metabolic alkalosis if the pH of a person’s blood is significantly higher than pH 7.45. A laboratory can also evaluate the concentration of chloride and potassium ions in the urine.

Treatment for metabolic alkalosis depends on the subtype a person has and the underlying cause.

Chloride-responsive metabolic alkalosis

A person with mild chloride-responsive alkalosis may only need to increase their intake of sodium chloride, or salt. The additional chloride makes the blood more acidic, which reduces the alkalosis.

This may involve increasing salt in the diet or taking an oral rehydration solution containing electrolytes if a person is experiencing vomiting or diarrhea. If they are unable to eat, this may take the form of administering salt via a saline drip through a vein.

Chloride-resistant metabolic alkalosis

Because chloride-resistant alkalosis does not occur due to a loss of electrolytes, doctors cannot treat it by giving saline alone. In some cases, this may make things worse. Instead, doctors focus on treating the underlying cause.

For example, ingesting too much sodium bicarbonate can result in poisoning. Treatment may involve IV fluids, taking activated charcoal, and medications to treat the symptoms.

Other causes may require other treatments, such as potassium supplementation, changing medications, or managing a chronic condition.

Metabolic alkalosis is relatively common. It is often mild, and treating the underlying condition usually cures it.

However, metabolic alkalosis can cause life threatening problems in some cases. This happens when it causes low calcium levels, which can lead to seizures or coma.

Therefore, anyone with symptoms of an electrolyte imbalance or other signs of metabolic alkalosis should contact a doctor to receive treatment.

Metabolic alkalosis occurs when the body’s pH level becomes too alkaline. This can occur if something disrupts the body’s pH balance, making the blood more alkaline than it should be.

Electrolyte imbalances cause metabolic alkalosis and can occur for a range of reasons. A person with dehydration or a kidney condition and those who take diuretics may be more at risk of developing metabolic alkalosis.

Anyone who is concerned they may have metabolic alkalosis should seek a professional opinion from a doctor.