How to tell if your body is alkaline or acidic?

September 21, 2025 •

4 min read

The human body tightly regulates its blood pH within a very narrow, slightly alkaline range of 7.35 to 7.45. Understanding how this complex system works and what truly affects your acid-base balance is crucial for debunking common health myths, including how to tell if your body is alkaline or acidic.

Quick Summary

The body maintains a stable blood pH through complex internal mechanisms, making it impossible to change with diet alone. While urine and saliva pH can vary and be tested at home, they don't reflect your body's overall state. Accurate assessment requires professional blood tests to diagnose serious underlying conditions like metabolic acidosis or alkalosis.

Key Points

Blood pH is tightly regulated: Your body, via the lungs and kidneys, maintains blood pH within a very narrow, slightly alkaline range of 7.35 to 7.45, regardless of diet.
Home test strips are unreliable for systemic pH: Urine and saliva pH fluctuate and do not accurately reflect your body's internal acid-base balance, which is a common misconception.
Diet influences waste, not blood pH: Eating an alkaline-forming diet can lead to more alkaline urine, but this is a sign that your kidneys are efficiently neutralizing and eliminating metabolic acids, not that your body is becoming alkaline.
True imbalances are medical issues: Metabolic acidosis or alkalosis are serious conditions caused by underlying diseases like kidney failure or uncontrolled diabetes, and require medical diagnosis and treatment, not dietary changes.
Focus on balanced nutrition: While the alkaline diet myth is debunked, its focus on fruits and vegetables is healthy for other reasons, including providing essential vitamins and minerals.
Professional testing is necessary for accuracy: The only way to get a true reading of your body's systemic pH is through a professional arterial blood gas (ABG) test performed by a healthcare provider.
Symptoms indicate deeper issues: If you experience symptoms like persistent fatigue, headaches, or nausea, they could indicate underlying issues, but they don't necessarily confirm an acid-base imbalance and should be evaluated by a doctor.

The Truth About pH: Understanding Acid-Base Balance

Many wellness trends promote the idea that diet can drastically alter your body's pH, suggesting that an "acidic" state leads to disease and an "alkaline" state promotes optimal health. The reality, supported by decades of medical research, is far more complex and involves sophisticated physiological systems that maintain a stable pH regardless of what you eat. Your blood pH is kept in a tightly controlled range between 7.35 and 7.45. If it falls outside this, it indicates a serious medical condition, not a dietary issue.

Can Home Tests Accurately Determine Your pH?

Home pH test strips for saliva and urine are widely available and can show fluctuations in the acidity or alkalinity of these fluids. However, these tests do not give you a reliable reading of your body's overall, systemic pH.

Urine pH: The kidneys play a critical role in filtering waste and maintaining the body's acid-base balance by excreting excess acids or bases in the urine. A highly acidic urine reading, for instance, might simply mean your kidneys are doing their job and eliminating acid waste effectively. It does not mean your blood is acidic. Your urine pH naturally fluctuates throughout the day based on your diet and hydration levels.
Saliva pH: The pH of your saliva is also influenced by many factors and does not reflect your blood's pH. While it can provide a snapshot of your oral environment, it is not an indicator of your systemic health.

The Difference Between Blood, Urine, and Saliva pH

To clear up the confusion surrounding different pH measurements, it's helpful to understand their individual roles and what they represent.


Feature	Blood pH	Urine pH	Saliva pH
Significance	Reflects systemic acid-base balance. Tightly regulated by lungs and kidneys.	Reflects how kidneys are eliminating excess acid or base. Naturally fluctuates.	A general indicator of oral health; not systemic health.
Normal Range	7.35–7.45 (very narrow)	4.0–8.0 (broad, varies)	6.5–7.5 (varies)
Best Test Method	Professional arterial blood gas (ABG) test	Home pH test strips	Home pH test strips
Result Interpretation	A pH outside this range indicates a serious medical condition.	Provides clues about how well your kidneys are functioning, but not about your body's overall pH.	Can show changes based on diet, but does not indicate overall body acidity.

When True Acid-Base Imbalances Occur

True metabolic acidosis and alkalosis are serious medical conditions, not lifestyle issues. They are caused by underlying diseases and require medical treatment, not dietary changes.

Metabolic Acidosis

This condition occurs when the body produces too much acid, or the kidneys cannot remove enough acid.

Common causes:

Uncontrolled diabetes (diabetic ketoacidosis)
Severe kidney disease or kidney failure
Severe dehydration
Intense, prolonged exercise (lactic acidosis)
Certain medications or poisons

Symptoms:

Deep, rapid breathing
Nausea and vomiting
Fatigue and weakness
Confusion

Metabolic Alkalosis

This condition occurs when the body has too much base (bicarbonate) or loses too much acid.

Common causes:

Excessive vomiting
Overuse of diuretics
Excessive intake of antacids
Certain adrenal gland disorders

Symptoms:

Numbness or tingling in the face, hands, or feet
Muscle twitching and cramps
Nausea
Lightheadedness or confusion

The Impact of Diet on Health, Not pH

While an "alkaline diet" cannot shift your blood pH, focusing on its principles—eating more fruits, vegetables, and plant-based foods—is beneficial for other health reasons. These foods are rich in vitamins, minerals, and fiber, promoting overall wellness.

Conversely, a diet high in processed foods, sugar, and red meat can be detrimental to health, not because it makes your body "acidic," but due to its association with inflammation, oxidative stress, and chronic diseases. The body uses mineral reserves, like calcium from bones, to neutralize metabolic acids, which can be taxing if the diet lacks sufficient nutrients. This is why a balanced diet is important, though not for the pH-altering reasons often touted.

The Final Verdict on Testing Your pH

If you are concerned about symptoms of a true acid-base disorder, seeking advice from a healthcare professional is the only reliable path. They can perform an arterial blood gas (ABG) test to measure your blood's pH accurately.

For everyday wellness, focus on a balanced, nutrient-rich diet with plenty of fruits and vegetables. Home test strips can provide some insight into your urine and saliva, but do not mistake these readings for your body's overall condition. The best way to maintain health is to support your body's natural systems, not to obsess over a mythical pH imbalance.

For more information on the body's natural buffer systems, visit the NCBI StatPearls article on Acid-Base Balance.

Frequently Asked Questions

While alkaline diets can't change your blood's pH, they are generally beneficial because they emphasize consuming more fruits, vegetables, and plant-based foods, which are rich in nutrients and fiber. These foods promote overall health, regardless of their effect on pH.

No. While they can indicate the pH of your urine or saliva at that moment, they do not provide a reliable measure of your blood's pH or your body's overall acid-base balance. The body has multiple buffering systems that ensure your blood pH remains stable.

Metabolic acidosis can be caused by conditions such as uncontrolled diabetes, kidney disease, severe dehydration, or lactic acid buildup from intense exercise. It is a serious medical condition requiring professional treatment.

Metabolic alkalosis is often caused by excessive vomiting, overuse of diuretics, or certain adrenal gland issues. It indicates an increase in the body's pH due to loss of acid or buildup of bicarbonate.

The healthy pH range for blood is very narrow, from 7.35 to 7.45. Any deviation outside this range is a serious medical issue that the body's compensatory mechanisms have failed to correct.

Blood pH is tightly regulated, while urine pH can fluctuate widely. The kidneys adjust urine pH to excrete excess acids or bases, helping to keep blood pH stable. Therefore, a change in urine pH is normal and reflects kidney function, not systemic acidity.

No, your body's natural buffering systems prevent food from significantly altering your blood's pH. While some foods are 'acid-forming' in terms of metabolic byproducts, these are processed and eliminated without impacting your blood's overall pH balance.