Metabolic Acidosis

Metabolic acidosis is when acids build up in your body fluids. It can affect anyone. But it commonly affects people who have kidney failure or chronic kidney disease (CKD).

Metabolic acidosis (met-uh-BOL-ik as-i-DOH-sis) can develop if you:

• Have too many acids in your blood that wipe out bicarbonate (high anion gap metabolic acidosis)
• Lose too much bicarbonate from your blood, usually from pee or poop (normal anion gap metabolic acidosis)

Bicarbonate is a base that can form after your body converts food to energy.

An anion gap is the difference between the positive and negative electric charges in the electrolytes in your blood. Electrolytes are ions. Ions are atoms or molecules that have an electrical charge. Electrolytes help regulate many metabolic processes in your body. These include bringing nutrients into your cells and taking waste products out of your cells.

What happens to your body if you have metabolic acidosis?

Your body must have a specific pH balance to function properly. The pH scale is the levels of acids and bases in your blood. It ranges from 0 (very acidic) to 14 (very basic or alkaline). A normal pH range in your blood is from 7.35 to 7.45.

Your kidneys and lungs help maintain a proper pH balance. Your kidneys remove excess acids and bases from your blood through your pee. Your lungs help manage acid levels by controlling the amount of carbon dioxide in your blood.

Metabolic acidosis occurs when your body has too much acid. It may also occur when your kidneys don’t remove enough acids from your blood.

Symptoms of metabolic acidosis

In some cases, you may not have any signs or symptoms. Symptoms of metabolic acidosis can vary. They can also look like symptoms of other diseases.

If you do have metabolic acidosis symptoms, they may include:

• Fast heartbeat (tachycardia)
• Confusion or dizziness
• Feeling very tired (fatigue)
• Loss of appetite
• Rapid breathing or long, deep breathing
• Nausea
• Vomiting
• Feeling weak
• Breath that smells sweet or fruity

What is the most common cause?

Severe diarrhea and kidney failure are the most common causes of metabolic acidosis. Both conditions can affect your body fluid, pH and electrolyte levels.

Other leading causes include:

• Diabetes-related ketoacidosis: This develops when ketone bodies build up from uncontrolled diabetes. Your body produces ketone bodies while it turns (metabolizes) fats into energy. Your body uses ketone bodies for energy when sugars (glucose) aren’t available.
• Diarrhea: This can result in metabolic acidosis due to your body losing too much bicarbonate in your poop. It may happen if you take too much medicine that makes you poop (laxatives) or have severe diarrhea.
• Lactic acidosis: This develops when you have too much lactic acid in your body. Lactic acid is an organic acid. Your muscle cells and red blood cells make it for energy when you don’t have a lot of oxygen in your body. Some causes include liver failure, low blood sugar and intense physical activity.
• Renal tubular acidosis: This develops when your kidneys don’t pass enough acids into your pee. As a result, your blood becomes more acidic.

Risk factors

You’re at a greater risk of metabolic acidosis if you have:

• An acute kidney injury (AKI)
• High potassium levels (hyperkalemia)
• Excess protein in your pee (albuminuria)
• Low red blood cell levels (anemia)
• Low fluid levels (dehydration)

Smoking and antifreeze poisoning can also increase your risk.

How to lower your risk

You can help reduce your risk by:

• Staying well-hydrated with water and other fluids
• Cutting back on how much alcohol you drink
• Managing your blood sugar levels if you have diabetes
• Eating lots of low-acid, high-alkali foods, like fruits, veggies and plant-based proteins
• Cutting back on foods that raise acid levels, like grains, egg yolks and meat
• Resting after intense physical activity

Complications

Without treatment, metabolic acidosis may cause complications like:

• Loss of bone mass (osteoporosis)
• Kidney damage
• High blood sugar (hyperglycemia)
• Loss of muscle
• Endocrine system problems, which may cause insulin resistance and diabetes

How doctors diagnose metabolic acidosis

Your healthcare provider will review your medical history and ask about your symptoms. They may also perform a physical exam. If they suspect metabolic acidosis, they’ll order tests. They may also refer you to a kidney specialist (nephrologist).

Tests that are used

Your healthcare provider may order blood or urine (pee) tests.

Blood tests

Blood tests help provide important information about chemicals in your blood. Metabolic acidosis blood tests may include:

• Anion gap: Your provider will compare your blood’s positive and negative electrolytes. A large gap may indicate metabolic acidosis.
• Arterial blood gas (ABG): This test measures the oxygen and carbon dioxide levels in your blood. It also measures your blood’s pH balance. A blood pH below 7.35 indicates that you have too much acid or too little base in your blood.

Urine tests

Your provider will check your pH level from a pee sample. You may have too many bases or not enough acids in your pee.

How do you fix metabolic acidosis?

Once your healthcare provider determines the cause, they can recommend a treatment plan. Some treatments include:

• Sodium bicarbonate or citrate (if you have CKD or kidney failure)
• IV fluids
• IV sodium bicarbonate, which balances the acids in your blood
• Insulin (if you have diabetes-related acidosis)
• Removing toxic substances from your blood, including aspirin, methanol (a substance in adhesives, paints and varnishes) and ethylene glycol (a substance in antifreeze)

What medications are used to treat it?

Your healthcare provider may recommend over-the-counter (OTC) medications, like sodium citrate and sodium bicarbonate. These can help balance the acids in your body. Talk to your provider before taking any OTC medications.

Can it go away on its own?

It depends on the cause of metabolic acidosis. Some mild cases go away without treatment or with a few lifestyle changes. Your healthcare provider will let you know what to expect.

When should I see my healthcare provider?

Reach out to your provider if you have symptoms of metabolic acidosis. You should also reach out if you have symptoms of a condition that may lead to it.

During your appointment, you may wish to ask questions like:

• Is my condition serious?
• If I don’t have metabolic acidosis, what other condition might I have?
• What tests do you recommend?
• What treatments do you recommend?
• Will lifestyle changes help?
• Should I see a nephrologist or another specialist?
• How often should I schedule follow-up appointments?

What can I expect if I have metabolic acidosis?

Your outlook depends on the severity and cause. Many cases of metabolic acidosis respond well to treatment after a proper diagnosis.

If you have a mild case, your symptoms may be temporary. You may not need any treatment. Severe cases can be fatal.