Disorders of Acid/Base Balance

The body does its best work at a pH of 7.4. If there is too much acid in the blood, then this can lead to bone and muscle loss. This can lead to kidney damage as well. Evaluation by the nephrologist can lead to the cause of the high acid levels and how best to manage it. The good news is that acid/base problems can often be found with a simple blood test and managed with steady, well-understood care.

How the body balances acid and base

Every cell in your body works best when the blood is kept in a very narrow range, close to a pH of 7.4. Even small shifts away from that point can affect how your organs do their jobs. To keep things steady, your body uses two main systems that act like a thermostat for acid.

The first is your lungs. When you breathe, you let out carbon dioxide, which behaves like an acid in the blood. Breathing a little faster or slower changes how much acid leaves your body, and this can happen within minutes.

The second is your kidneys. Your kidneys remove acid in the urine and make a buffer called bicarbonate that soaks up extra acid, much like baking soda neutralizes vinegar. The kidneys work more slowly than the lungs, over hours to days, but they handle the steady load of acid your body makes from food and normal activity.

When both systems are healthy, they keep acid and base in balance without you ever noticing. A disorder happens when one of these systems cannot keep up.

When the balance is off (acidosis and alkalosis)

Doctors describe acid/base problems in two broad directions.

• Acidosis means there is too much acid, or not enough buffer, in the blood. Metabolic acidosis comes from the kidneys or from the body making extra acid, and it is one of the more common problems in chronic kidney disease. Respiratory acidosis comes from the lungs not clearing enough carbon dioxide.
• Alkalosis means there is too little acid, or too much buffer. Metabolic alkalosis can follow heavy vomiting or the use of certain medicines, such as some water pills. Respiratory alkalosis can happen with fast breathing.

In kidney disease, metabolic acidosis is the type that comes up most often. As the kidneys lose function, they cannot remove the daily acid load or make enough bicarbonate, so acid slowly builds up.

Many people with a mild imbalance feel completely normal, which is why these problems are often found on routine blood work rather than from symptoms. When symptoms do appear, they can be vague, such as tiredness, weakness, or faster breathing.

Why it matters (bones, muscles, and kidney health)

Carrying extra acid in the blood for a long time is not harmless, even when you feel fine.

To buffer the acid, the body may pull minerals out of the bones. Over months and years, this can weaken bones and is linked to bone disease. You can read more about how kidney problems affect the skeleton on our bone health page.

Extra acid can also break down muscle protein, which may lead to loss of strength over time. And research suggests that ongoing acidosis can speed up the decline of kidney function itself, creating a cycle where weaker kidneys allow more acid to build up.

Because acid/base balance is closely tied to other lab values, an imbalance can travel with shifts in minerals such as potassium. If you would like to learn more about a related lab problem, see our page on disorders of potassium balance.

The takeaway is simple: keeping acid levels near normal helps protect your bones, your muscle strength, and your remaining kidney function.

How we evaluate it (blood tests, including bicarbonate/CO2)

Acid/base problems are usually found and followed with blood tests, not guesswork.

A common starting point is the bicarbonate level, which often appears on lab reports as CO2 or total CO2 in a basic metabolic panel. A lower-than-normal value can be a sign of metabolic acidosis. This test is often already part of routine blood work, so a problem may be spotted before you have any symptoms.

To understand the full picture, a provider may also look at other clues, which can include:

• Kidney function tests, such as creatinine and the estimated glomerular filtration rate (eGFR)
• Electrolyte levels, including potassium, sodium, and chloride
• In some cases, a blood gas test, which measures acid levels and oxygen more directly

The aim of evaluation is twofold: to confirm whether the balance is truly off, and to find the cause. Knowing the cause is what guides the right treatment, since acidosis from kidney disease is handled differently from acidosis caused by another condition.

How acid/base problems are treated (general)

Treatment is tailored to the person and starts with addressing the underlying cause. There is no single fix that fits everyone, which is why a careful evaluation comes first.

In general terms, care may include:

• Treating the root cause, such as managing chronic kidney disease, adjusting medicines that affect acid levels, or addressing another illness contributing to the imbalance.
• Raising bicarbonate when it is low. When metabolic acidosis is linked to kidney disease, a provider may prescribe oral bicarbonate, sometimes called baking soda in tablet form, to bring the level back toward normal.
• Diet adjustments, since some eating patterns add more acid and others, such as more fruits and vegetables, can be gentler on the body. Any diet change should fit your overall kidney plan.

Because the right approach depends on your labs, your kidney function, and your other conditions, treatment decisions and any doses are made by your provider, not from a general guide. Managing acidosis can also be one part of a broader plan to support kidney function. You can learn more on our care for impaired kidney function page.

When to see a nephrologist

It is worth talking with a kidney specialist if a blood test shows a low bicarbonate or CO2 level, if you have chronic kidney disease, or if your primary care provider notices a pattern on your labs. A nephrologist can sort out whether the imbalance comes from your kidneys, your lungs, your medicines, or another condition, and then build a plan to manage it.

You do not need to wait for symptoms. Because acid/base problems are often silent, the best time to act is when the labs first point to a concern, so any harm to your bones, muscles, and kidneys can be limited.

If you have questions about a lab result or a recent diagnosis, our team is here to help you understand what it means and what to do next. With steady monitoring and the right plan, acid/base balance is a problem that can usually be managed well over time.