PH balance is a state of the body in which the balance between cations (positive ions) and anions (negative ions) in body fluids is maintained. It determines the correct pH and functioning of the body. The pH value is closely related to the area of the body. The lowest pH is in the stomach. It is related to the digestive function of gastric juice. Such a low pH also protects the body from pathogens.
The skin also has a fairly acidic pH, which creates a protective coat against microorganisms' penetration into the body. The pH of urine can fluctuate. It is related to the regulatory function of the kidneys. If the pH in the body is too high (alkalosis) or too low (acidosis), substances are secreted, which leads to their equalization. The diet also affects the pH of urine.
The blood's pH remains fairly constant. This is related to specialized regulatory forms called buffers. A pH of 7.35-7.4 is optimal for most life processes. For this reason, acid-base imbalances are very dangerous and lead to many changes in the human body's processes.
The body's pH balance
is maintained thanks to two main components: undisturbed ventilation in the lungs and excretion in the kidneys.
The lungs supply oxygen (O2) to the blood and tissues and remove carbon dioxide (CO2), the excess of which accumulates in the body as a product of cellular respiration, necessary for obtaining energy.
The kidneys can reabsorb appropriate substances into the blood or secrete them into the urine, depending on the need (the most important are HCO3 ions).
In physiological conditions, small fluctuations in the concentrations of gases and ions dissolved in the blood are efficiently balanced to maintain the pH of body fluids within a very narrow range of values. This is necessary to enable the proper functioning of all body processes.
Problems leading to acid-base imbalance can be divided into respiratory (caused by inadequate ventilation and O2, CO2 levels, and lung problems) and metabolic (caused by the presence of certain substances, fluctuations in the concentration of potassium, hydrogen, and chloride ions, and kidney disorders). Several diseases, conditions, and medications also facilitate such situations. In these cases, the body fails to maintain a constant blood pH and drops (acidosis) or increases (alkalosis), which has several consequences.
Diagnosing those issues includes the following measurements: pH – hydrogen ion concentration on a logarithmic scale, pCO2 – partial pressure of carbon dioxide, pO2 – partial pressure of oxygen, and HCO3- – bicarbonate concentration.
When the body becomes too acidic, it triggers processes to correct the pH balance. Other systems will compensate if an organ responsible for maintaining the balance malfunctions. If the initial acidifying factor persists, the body's pH control mechanisms can become overwhelmed, resulting in acidosis (pH<7.35), which can have harmful effects.
In acidosis, the following occur: increased glucose production in the liver, breakdown of fat tissue, increased breakdown of proteins, disturbances in ion metabolism—increased potassium levels, which can lead to heart rhythm and muscle weakness—intensified lung ventilation (in non-respiratory acidosis)—in severe cases, rapid and deep breathing may occur to eliminate carbon dioxide from the body.
When the body becomes too alkaline, the balance of certain chemicals is affected. Low potassium levels in the blood can lead to dangerous heart rhythm disturbances and muscle weakening. Alkalosis may also cause symptoms similar to tetany due to low calcium levels. Tetany can cause numbness and muscle spasms in the hands and may spread to the arms, chest, and legs, resembling an epileptic seizure, but the person remains conscious during a tetany attack.
The equivalents of tetany, i.e., symptoms that may conceal hypocalcemia accompanying alkalosis, are:
Correction of pH balance disorders that lead to alkalosis occurs up to a certain point with the participation of the urinary system in the form of increased excretion of bicarbonate ions in the urine (“alkaline”) and a reduction in the processes of producing these ions. The consequence is a gradual decrease in pH and the restoration of isotonic – the correct, constant composition of the body's ions.
Acidosis is a state of imbalance in the body's homeostasis, which can have severe clinical implications. It occurs when the regulation of the body's pH balance is impaired, leading to conditions such as renal failure, impaired respiratory function in diseases like chronic obstructive pulmonary disease (COPD) or right ventricular heart failure, systemic diseases including diabetes and chronic diarrhea, and body hypoxia. Additionally, acidosis can result from alcohol, salicylate, and ethylene glycol poisoning.
Conversely, alkalosis, characterized by a pH level higher than 7.45, occurs when the body's ability to compensate for pH balance disorders is overwhelmed. It is often linked to imbalances such as potassium and hydrogen deficiencies caused by factors like glucocorticosteroids, excessive loss of hydrogen ions through persistent vomiting, potassium loss in the urine due to diuretics, or hyperventilation. Various factors, including stimulation of the respiratory center, hypoxia, and mental disorders, can also lead to alkalosis due to hypocapnia.
A blood pH value deviating beyond 7.35-7.45 indicates acidity or alkalinity. Acidosis occurs when the pH falls below 7.35, while alkalosis occurs when the pH rises above 7.45. It is important to note that a standard pH value does not necessarily exclude severe medical conditions. Therefore, a qualified medical professional should evaluate test results and their correlation with the patient's clinical condition.
In assessing pH balance, the concentration of bicarbonate ions (HCO3-) and the partial pressure of carbon dioxide (pCO2) are important indicators. Acidosis and alkalosis are categorized into respiratory and non-respiratory types and compensated and uncompensated forms.
Compensated acidosis or alkalosis occurs when the pH remains within the normal range despite abnormal HCO3—or pCO2 concentrations, indicating efficient compensatory mechanisms. Uncompensated acidosis or alkalosis occurs when these mechanisms are overwhelmed.
A decrease in HCO3- levels accompanied by a low pH indicates non-respiratory acidosis, while an increase in pCO2 levels coupled with a pH decrease indicates respiratory acidosis. Respiratory alkalosis is characterized by an increase in pH and a decrease in pCO2, while non-respiratory alkalosis involves an increase in bicarbonate ions.
Blood gasometry is ordered to confirm or rule out disorders in the pH balance. It allows for assessing the type of disorder, determining its cause, and measuring the effectiveness of compensatory processes (those that have occurred in the body to compensate for and counteract the irregularities that have occurred).
It is used to diagnose acute respiratory failure (sudden breathing problems) and monitor the effectiveness of treatment (including oxygen therapy) in chronic respiratory failure (caused by lung diseases such as inflammation, COPD, and asthma).
It may also be helpful in the case of suspected poisoning with various substances, after head and neck injuries that may affect breathing, procedures involving general anesthesia, and acute, generalized infections (especially in the gastrointestinal tract).
Other diseases in which the test is widely used include kidney diseases (congenital or acquired) and metabolic diseases (related to the metabolic pathways of carbohydrates, proteins, and fats).
People with symptoms that may indicate pH balance disorders:
Remember that blood gasometry is utilized to assess the pH balance or imbalance in the body.
Treatment should target the underlying cause of acidosis or alkalosis. For instance, if acidosis is associated with kidney disease, a nephrologist should monitor the patient. In contrast, a patient with chronic obstructive pulmonary disease should be under the care of a pulmonologist. The same principle applies to treating alkalosis.
However, in the case of acute systemic diseases requiring urgent medical intervention, such as alkalosis with tetany attacks, ketoacidosis, or untreated lactic acidosis, which can lead to severe consciousness disturbances, including coma, the approach differs.
The mineral content of food and our diet influences the body's pH balance. These minerals are released during digestion and impact the body's internal pH levels, acting as acidic or alkaline agents. Acid-forming minerals primarily include chlorine, phosphorus, and sulfur, while alkaline-forming minerals mainly comprise calcium, sodium, potassium, and magnesium. Food products' acid-forming and alkaline minerals vary, affecting the body's pH balance based on meal compositions.
Most foundational dietary products contain dominant amounts of acid-forming minerals, particularly in meat, poultry, fish, eggs, and, to a lesser extent, cereal products. Conversely, alkaline minerals are primarily found in vegetables (excluding peas and soy, which are predominantly acidifying), fruits, and milk. The potential alkalizing capacity of these products is generally lower than the potential acidifying impact of meat products. Consequently, a diet that maintains pH balance should include alkaline products.
During food processing, mineral loss (e.g., through refining or leaching) or changes in bioavailability can affect products' acidifying or alkaline potential. For instance, the production of cottage cheese from milk leads to a significant transfer of calcium into the whey, resulting in low calcium content in cottage cheese and an overall acidifying effect. Among essential nutrients, proteins and fats tend to have an acidifying impact on the body.
A diet high in fats combined with low carbohydrate intake (ketogenic diet) leads to partially combusted lipid byproducts (acetoacetic acid and hydroxybutyric acid), further intensifying the acidifying effect of fats. Urine pH serves as a simple indicator of the body's pH balance. With a balanced diet, urine pH tends to be slightly acidic, whereas vegetarians (exclusively consuming a non-animal diet) exhibit neutral urine pH, and individuals with high meat consumption showcase acidic urine pH. It's important to note that dietary patterns cause changes in the pH balance, which the body's adaptive mechanisms can compensate.
Diseases affecting the pH balance necessitate hospital treatment and are often associated with respiratory and circulatory system disorders, as well as drug poisoning.
Table of Contents
Electrolytes are salt ions necessary for good health. The proper functioning of the whole organism depends on their proper level.… read more »
Lactic acid is an organic chemical compound used in various industries. Lactic acid bacilli are essential for health. Learn more… read more »
Hypokalemia means potassium deficiency, a decrease in potassium in blood below 3.5 mmol/L. It can have various causes, and most… read more »
Kidney stones can form for a variety of reasons. Learn about factors that increase the risk of kidney stones. See… read more »
Hypercapnia is a condition in which the partial pressure of carbon dioxide in our blood is increased. This can be… read more »
Dehydration can cause many negative health effects. It is a common problem in children and seniors. Learn how to recognize… read more »
In chronic acid reflux, also known as gastroesophageal reflux disease (GERD), excessive acid in the stomach flows back to the… read more »
Hydronephrosis is a disease that can have serious complications. Find out how to recognise the condition so that appropriate treatment… read more »
Kidneys are two bean-shaped organs that filter your blood from waste products. What are its other functions? How are they… read more »
