Is acid or alkaline worse? The definitive guide to body pH balance

October 2, 2025 •

4 min read

The human body is an expert at maintaining a very specific, slightly alkaline pH balance in its blood, typically between 7.35 and 7.45. It is not a matter of whether is acid or alkaline worse, but rather how the body’s sophisticated buffering systems manage to keep this critical equilibrium in check, as significant deviation in either direction signals serious health issues.

Quick Summary

The body’s natural pH regulation systems, involving the lungs and kidneys, keep blood pH within a very narrow, slightly alkaline range; any severe deviation, whether too acidic (acidosis) or too alkaline (alkalosis), indicates an underlying medical problem and is equally dangerous. It is not beneficial to push the body to either extreme, as the body strives for a stable, healthy balance.

Key Points

Blood pH is tightly regulated: Your body maintains a very specific, slightly alkaline blood pH (7.35-7.45) using the lungs and kidneys.
Both acidosis and alkalosis are dangerous: Severe deviations from a balanced blood pH, whether too acidic or too alkaline, indicate a serious underlying medical problem.
Diet does not change blood pH: A healthy diet, even one rich in fruits and vegetables, does not significantly alter your blood pH, contrary to alkaline diet claims.
Acidosis causes: Can result from diabetes, kidney failure, lung disease (like COPD), or drug overdose.
Alkalosis causes: Can result from prolonged vomiting, dehydration, or hyperventilation (e.g., during a panic attack).
Extreme imbalances require medical attention: Attempting to correct a severe pH imbalance with home remedies is ineffective and can delay necessary medical treatment.
Diet for better health, not pH control: Focus on eating a balanced, nutritious diet for overall health benefits, not for the unproven purpose of altering your body's pH.

Understanding the Body's pH Balance

The pH scale is a measure of how acidic or basic a substance is, ranging from 0 (most acidic) to 14 (most basic or alkaline), with 7 being neutral. For the human body, the pH balance is not a one-size-fits-all concept. Different parts of the body have different, crucial pH levels. For example, your stomach is highly acidic (pH 1.5–3.5) to break down food, while your small intestine is alkaline to aid in nutrient absorption.

The Body's Buffering System: Lungs and Kidneys

Your body possesses a highly sophisticated system to keep your blood pH stable, even when faced with changes from diet or metabolism. This process is called homeostasis. The lungs regulate pH by controlling the amount of carbon dioxide (an acid) exhaled. Breathe faster and deeper, and you expel more CO₂, raising blood pH. The kidneys, a slower but more powerful system, excrete excess acids or bases into the urine to maintain balance. This tight control means that, for a healthy person, diet cannot significantly alter blood pH.

The Dangers of Acidosis (Too Much Acid)

Acidosis occurs when your blood pH falls below 7.35. It is a serious medical condition, not something caused by a slight dietary change. It can result from a number of medical issues.

Causes of Acidosis

Metabolic Acidosis: Occurs when the body produces too much acid or the kidneys can’t remove enough of it. Common causes include diabetes (leading to ketoacidosis), severe kidney disease, or extreme diarrhea, which causes a loss of bicarbonate.
Respiratory Acidosis: Happens when your breathing is inadequate, causing carbon dioxide to build up in your blood. This can be a result of chronic lung diseases like COPD, asthma, or drug overdose.

Symptoms of Acidosis

Symptoms can range from mild to severe and include nausea, vomiting, fatigue, headache, confusion, and rapid breathing. Left untreated, severe acidosis can lead to shock, coma, and even death.

The Dangers of Alkalosis (Too Much Alkaline)

Alkalosis is the equally dangerous condition where your blood pH rises above 7.45. Like acidosis, it is a sign of an underlying medical problem, not a desirable state.

Causes of Alkalosis

Metabolic Alkalosis: Caused by a buildup of bicarbonate or a loss of acid from the body. This can be caused by prolonged vomiting, dehydration, or kidney disease.
Respiratory Alkalosis: Occurs when you breathe too fast or too deeply, causing you to exhale too much carbon dioxide. This can be triggered by anxiety, panic attacks, or high altitude.

Symptoms of Alkalosis

Symptoms can include irritability, muscle cramps, twitches, and tingling or numbness in the extremities. In severe cases, it can cause muscle spasms, confusion, and even unconsciousness.

Comparison: Acidosis vs. Alkalosis


Feature	Acidosis (Too Much Acid)	Alkalosis (Too Much Alkaline)
Underlying Cause	Metabolic or respiratory problems	Metabolic or respiratory problems
Blood pH Level	Below 7.35	Above 7.45
Main Symptoms	Nausea, vomiting, fatigue, headache, rapid breathing	Muscle cramps, twitches, tingling, confusion, irritability
Primary Organs Affected	Lungs and kidneys attempt to compensate	Lungs and kidneys attempt to compensate
Severity	Both can be life-threatening if untreated	Both can be life-threatening if untreated
Dietary Impact	Not directly affected by a healthy diet	Not directly affected by a healthy diet

The Truth About the Alkaline Diet

Amidst the discussion of body pH, you may have encountered the trend of the alkaline diet. Proponents claim that eating certain foods can raise your blood pH and prevent diseases like cancer, as cancer cells supposedly thrive in acidic environments. However, this is a myth.

While eating fruits, vegetables, and other foods promoted by the alkaline diet can lead to better health, it is not because they change your blood's pH. As established, your body's systems (lungs, kidneys) prevent this from happening. The benefits come from the nutritious foods themselves. Eating a balanced diet rich in fruits and vegetables is widely recommended for better health, but its positive impact is independent of its effect on blood pH. You can read more about dietary health from a reliable source like the American Institute for Cancer Research.

Conclusion: Seeking Balance, Not Extremes

In the context of systemic health, the question is acid or alkaline worse is misleading. A healthy body is naturally equipped to handle its own acid-base balance, and extreme deviations in either direction are equally dangerous and indicate a serious medical problem. Focus on supporting your body's natural processes with a healthy lifestyle, including a balanced diet and regular exercise. If you experience persistent or severe symptoms related to pH imbalance, seek medical attention immediately. Attempting to self-correct a severe imbalance with diet or supplements can be harmful and ineffective.

Frequently Asked Questions

No, it is not. Your body tightly regulates its blood pH to a slightly alkaline state (7.35-7.45) for optimal function. The idea that a higher alkaline state is healthier is a misconception, as severe alkalosis (too alkaline) is a dangerous medical condition.

No, diet cannot significantly change your blood's pH. The lungs and kidneys work diligently to keep your blood pH within a very narrow, healthy range, and they will excrete excess acid or alkali from your body to maintain this balance.

Symptoms of a pH imbalance depend on whether you are in acidosis or alkalosis. They can include fatigue, nausea, vomiting, headache, confusion, muscle cramps, or tingling. These are typically symptoms of a serious medical condition and warrant a doctor's visit.

The alkaline diet's premise—that it can alter blood pH and prevent disease—is not supported by scientific evidence. While eating the nutrient-rich foods promoted by the diet can improve health, it's not due to a change in your blood's pH level.

While some research suggests that cancer cells may grow in acidic environments within tumors, an alkaline diet cannot alter your blood's pH to affect cancer. Proven strategies like a healthy diet and lifestyle, not pH manipulation, are the recommended ways to reduce cancer risk.

Acidosis, or an excess of acid in the blood, can be caused by various medical conditions, including severe kidney disease, diabetes, or lung diseases like COPD. It is not caused by eating acidic foods like lemons.

Alkalosis, an excess of alkali in the blood, can result from prolonged or severe vomiting, which causes a loss of stomach acid. It can also be caused by hyperventilation, where too much carbon dioxide is exhaled, typically during a panic attack or in high altitude.