Metabolic Acidosis: Causes & Treatments

Metabolic acidosis occurs due to increased acidic pH in the blood when lung and kidney cells fail to regulate the pH balance. It is usually a result of uncontrolled diabetes and kidney diseases. Read on to learn more about the causes and treatment of metabolic acidosis.

What is metabolic acidosis?

Metabolic acidosis is defined as having a pH level lower than 7.35 of arterial blood gas with a plasma bicarbonate level lower than 22 mmol/L. Bicarbonate (also called alkali) is a salt of carbonic acid containing the ion HCO3. An anion gap develops due to the difference between the ions having positive or negative electric charges in the electrolytes within different body fluids.

The lowering of arterial blood pH occurs as a result of too much acid in the blood and leads to a state called “high anion gap metabolic acidosis.”

What happens in the body when you have metabolic acidosis?

Maintaining a specific pH balance in the blood is essential for ensuring that vital organs can function properly. The pH scale ranges between 0 (very acidic) and 14 (very alkaline or basic). The normal pH range in the blood is between 7.35 and 7.45.

The kidneys and lungs play a key role in maintaining the normal pH balance. The kidneys help to remove excess bases and acids from your body through the urine. The lungs help to maintain the pH balance by regulating the amount of carbon dioxide circulating in the blood. Metabolic acidosis develops when the body produces excess acid in the blood that the kidneys cannot remove.

What are the symptoms of Metabolic Acidosis?

People with metabolic acidosis often do not have any symptoms. However, some common warning signs of metabolic acidosis can include the following:

Increased heart rate (tachycardia)
Labored or rapid breathing
Confusion
Dizziness
Unusual tiredness
Frequently elevated blood sugar levels
Headache
Loss of appetite
Breath that smells fruity or sweet
Nausea and vomiting

What are the metabolic acidosis causes and risk factors?

Metabolic acidosis can affect anyone, although patients who have an underlying disease such as kidney failure or chronic kidney disease are more vulnerable to developing renal tubular acidosis due to the loss of kidney function and the inability to filter and excrete excess ions for maintaining the pH balance in the blood. Uncontrolled diabetes is also a common cause of metabolic acidosis.

Metabolic acidosis that occurs as a result of renal failure or any other kidney disease is called “normal anion gap metabolic acidosis.” This is when you lose too many base ions (alkaline) in the form of bicarbonates.

There are different causes and types of metabolic acidosis to be aware of. Below are four of the most common causes of metabolic acidosis.

Diabetic acidosis

Diabetic acidosis develops as a result of the build-up of substances called ketone bodies in the blood, usually due to improperly treated or uncontrolled diabetes.

Ketones are released after fat is converted into a usable energy source. Ketone bodies serve as the secondary fuel source for the body, used only when carbohydrates are not available.

Diabetic ketoacidosis develops when the body cannot use glucose to fuel its cellular functions, forcing it to break down fat and release excess ketone bodies.

Hyperchloremic acidosis

Hyperchloremic acidosis occurs from a loss of sodium bicarbonate. It may occur due to dehydration following severe diarrhea or the prolonged or over-use of laxatives. It can also be caused by toxin ingestion of methanol or ethylene glycol. Ethylene glycol is a substance found in antifreeze.

Renal tubular acidosis

Renal tubular acidosis occurs when kidney function is affected, preventing the efficient elimination of acidic ions in the urine, thus disrupting the pH balance. This causes the blood to become more acidic, leading to metabolic acidosis.

Lactic acidosis

Lactic acidosis results from releasing too much lactic acid in the body. Lactic acid is an organic acid produced by red blood cells and muscle cells during the generation of energy when you do not have enough supply of oxygen.

Common causes of lactic acidosis include low blood sugar, liver failure, drinking too much alcohol, exercising vigorously for an extended period of time, cancer, carbon monoxide poisoning, heart failure, and certain medications.

How does a doctor diagnose Metabolic Acidosis?

Your doctor may prescribe different tests to diagnose different types of metabolic acidosis. Blood tests are the most commonly recommended. Below is a breakdown of the different types of tests done to diagnose acidosis.

Anion Gap

Anion gap blood tests can provide levels of different chemicals in your blood. A sample of blood is drawn from your arm to compare the difference between the positively charged and negatively charged electrolytes present. A large gap between the positive and negative electrolytes in the blood could point to the diagnosis of metabolic acidosis. Electrolytes, such as sodium and potassium levels, help regulate several metabolic processes.

Arterial Blood Gases (ABG)

Arterial blood gas tests use a sample of blood from an artery in your arm, wrist, or groin to measure the blood’s pH balance, oxygen, and carbon dioxide levels. A blood pH lower than 7.35 indicates that you have a higher level of acids or a lower level of bases in your blood, suggesting the diagnosis of metabolic acidosis. Additional tests may be performed to assess kidney function.

Urine Tests

Your healthcare specialist may also perform urine tests to measure lactic acid and pH levels. Too much acid in the urine can help diagnose acidosis.

How do you treat Metabolic Acidosis?

The treatment of metabolic acidosis depends on the underlying cause. It’s important seek timely medical intervention to restore the body’s pH balance and sodium bicarbonate levels as soon as possible. Delayed diagnosis and treatment of severe metabolic acidosis can lead to adverse effects on the kidneys, bones, and muscles. Very severe metabolic acidosis, especially diabetic ketoacidosis, tends to progress rapidly, putting patients at risk of a coma or even death.

Common treatment options to restore the acid-base balance in the body and prevent the complications of severe metabolic acidosis include:

Sodium bicarbonate: Sodium bicarbonate may be prescribed to restore the healthy pH of the blood and body fluids in cases of proximal renal tubular acidosis and distal renal tubular acidosis. Sodium bicarbonate can also be administered intravenously to rapidly replenish the loss of base ions in patients with hyperchloremic acidosis.
Diet: Diet changes are seen as one of the most effective strategies for reducing the risk of metabolic acidosis, reducing acid load, and improving alkali levels. Increase your intake of foods like apples, berries, grapes, spinach, lettuce, sweet potatoes, and legumes to help lower the acid load in the blood. You should also limit acid ingestion, so eat fewer foods that stimulate acid production, such as cheese, eggs, meats, and cereal grains.

Other treatment options for metabolic acidosis include:

IV fluids to dilute the excess lactic acid and other acidic ions.
Sodium citrate to treat acidosis from kidney failure.
Detoxification when acidosis is suspected to be the result of drug overuse or alcohol poisoning.
Intravenous (IV) fluids and insulin for the management of diabetic ketoacidosis.
Other lactic acidosis treatment includes oxygen and antibiotics, depending on the cause.

The most effective and simple ways to restore the pH balance and prevent metabolic acidosis include:

Increase your intake of water and other fluids to stay hydrated.
Reduce simple sugar intake to maintain your blood sugar levels within normal limits and control diabetes.
Limit your intake of alcohol.

If you have an underlying disease, such as chronic kidney disease, kidney failure, diabetes, or another underlying disease causing too much acid in the blood or other body fluids, it’s important that you talk to your doctor immediately.

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