What is metabolic acidosis?
The buildup of acid in the body due to kidney disease or kidney failure is called metabolic acidosis. When your body fluids contain too much acid, it means that your body is either not getting rid of enough acid, is making too much acid, or cannot balance the acid in your body.
What causes metabolic acidosis?
Healthy kidneys have many jobs. One of these jobs is to keep the right balance of acids in the body. The kidneys do this by removing acid from the body through urine. Metabolic acidosis is caused by a build-up of too many acids in the blood. This happens when your kidneys are unable to remove enough acid from your blood.
What are the signs and symptoms?
Not everyone will have signs or symptoms. However, you may experience:
- Long and deep breaths
- Fast heartbeat
- Headache and/or confusion
- Feeling very tired
- Vomiting and/or feeling sick to your stomach (nausea)
- Loss of appetite
If you experience any of these, it is important to let your healthcare provider know immediately.
What are the complications of metabolic acidosis if I have kidney disease or kidney failure?
- Increased bone loss (osteoporosis): Metabolic acidosis can lead to a loss of bone in your body. This can lead to a higher chance of fractures in important bones like your hips or backbone.
- Progression of kidney disease: Metabolic acidosis can make your kidney disease worse. Exactly how this happens is not clear. As acid builds up, kidney function lowers; and as kidney function lowers, acid builds up. This can lead to the progression of kidney disease.
- Muscle loss: Albumin is an important protein in your body that helps build and keep muscles healthy. Metabolic acidosis lowers the amount of albumin created in your body, and leads to muscle loss, or what is called “muscle wasting.”
- Endocrine disorders: Metabolic acidosis interferes with your body’s ability to maintain normal functions of your endocrine system (the collection of glands that produce hormones). This can cause your body to build a resistance to insulin (the hormone in your body that helps keep your blood sugar level from getting too high or too low). If left untreated for too long or not corrected in time, it can lead to diabetes.
How is it treated?
Bicarbonate: We all need bicarbonate (a form of carbon dioxide) in our blood. Low bicarbonate levels in the blood are a sign of metabolic acidosis. It is an alkali (also known as base), the opposite of acid, and can balance acid. It keeps our blood from becoming too acidic. Healthy kidneys help keep your bicarbonate levels in balance. Low bicarbonate levels (less than 22 mmol/l) can also cause your kidney disease to get worse. A small group of studies have shown that treatment with sodium bicarbonate or sodium citrate pills can help keep kidney disease from getting worse. However, you should not take sodium bicarbonate or sodium citrate pills unless your healthcare provider recommends it.
Diet: Increasing fruit and vegetable intake may decrease acid load in the body. This is because fruits and vegetables produce alkali, whereas foods such as meats, eggs, cheese, and cereal grains cause the body to make acid. Your kidney dietitian can show you how to safely increase the right type and amounts of fruits and vegetables in your diet based on your stage of kidney disease.