pH in the blood

What is the normal pH level in the blood?

The normal pH value in the blood is between 7.35 and 7.45. Keeping the pH value in the blood constant is important for maintaining all body functions.

This is mainly due to the fact that the structure of the body's proteins is highly dependent on pH. If the pH value is derailed, life-threatening complications arise.

Various buffer systems enable the pH value of the blood to remain constant and compensate for minor fluctuations that can arise, for example, from diet. The totality of all factors that determine and regulate the pH are collectively referred to as the "acid-base balance".

You can find more helpful information on this topic at: pH value in humans

Is there an optimal pH?

The pH value is subject to natural fluctuations that reflect the metabolic state. It is not possible to determine a certain optimal pH value.

It is important that the natural fluctuations remain within a range between 7.35 and 7.45 so that the body functions can be maintained. An optimal pH is accordingly in this range and is kept constant by the body under normal circumstances.

How can you measure the pH in the blood?

The pH value in the blood is usually measured as part of the blood gas analysis. Blood is taken either from a vein, an artery or from the earlobe with a lancing device and analyzed with special blood gas analysis devices.

These devices combine a large number of chemical test methods and determine not only the pH value but also other values ​​such as the content of oxygen or carbon dioxide in the blood.

The results of the blood gas analysis show the cause of the pH value derailment and treat it accordingly.

The measuring principle for pH value measurement is based on the conductivity for electrical current, which differs depending on the pH value. There are currently no ways to measure blood pH in the home.

In contrast, there are test strips that can be used to measure the pH value in urine. However, this is subject to even greater fluctuations and one cannot necessarily infer the pH of the blood from the urine pH.

For more information on this topic, see: Blood gas analysis

What increases the pH?

An increased pH value means that the blood is too basic or not acidic enough. The technical term for this pH increase is alkalosis. Alkalosis can have various causes.

Two different causes for an increased pH value can be roughly distinguished.

  1. Altered breathing:
    The first cause is a change in breathing. An alkalosis caused by altered breathing is called "respiratory alkalosis". The causal change in breathing is hyperventilation, i.e. very fast and deep breathing.
    In this type of breathing, too much carbon dioxide is exhaled. Carbon dioxide is an acid when dissolved in water, so increased loss will cause the pH to rise.
  2. Metabolic changes:
    The second cause of alkalosis is metabolism. The resulting alkalosis is called "metabolic alkalosis".
    Disturbances in the salt balance, such as a lowered potassium level, lead to an alkaline metabolism. Persistent or violent vomiting leads to a loss of acidic stomach acid and an increased pH value.
    Medicines can also lead to a basic pH value. Antacids, i.e. acid-binding drugs that are taken for acid-related stomach complaints and heartburn, lead to an increased pH value by binding acid in the stomach.

How can I increase the pH level in my blood myself?

The pH value in the blood must be kept constant in order to maintain organ functions. Derailments occur with serious illnesses. If the pH value changes significantly, treatment in an intensive care unit may be necessary.

Since the body usually keeps the pH constant within a narrow range, there is no need to take any action to increase the pH. A slightly reduced pH caused by a change in breathing is compensated by the body by changing metabolic processes.

If the breathing disturbance persists or the compensatory capacity is exhausted, the pH drops again and life-threatening pH values ​​can occur.

However, if a lowered pH is caused by changes in the metabolism, e.g. if you have ketoacidosis as part of the Diabetes mellitus, the body reacts with hyperventilation to breathe out carbon dioxide and thereby increase the pH again.

Read more about this topic under: Hyperventilation

What are the long-term consequences of a permanently increased pH value?

An increased pH value makes it more difficult for the blood to release oxygen to the tissue, as the oxygen is more firmly attached to the red blood pigment of the red blood cells (Erythrocytes) is bound. The result is an undersupply of the tissue.

If the body's compensation mechanisms fail, the organs are not adequately supplied and can be damaged as a result.

Another consequence is a decrease in the potassium level in the blood, cardiac arrhythmias and general muscle weakness can occur.

Further information on this topic is available at: Potassium Deficiency - How Does It Come About?

What lowers the pH?

A lowering of the pH value, called acidosis, can also be caused by changes in breathing and changes in metabolism.

  1. Altered breathing:
    In the case of acidosis caused by changes in breathing (respiratory acidosis) there is a reduced exhalation of carbon dioxide.Disturbance of the gas exchange in the lungs or a disturbance of the breathing itself, i.e. a reduced breathing rate or breathing depth can be the cause.
    A complete respiratory standstill has a particularly strong effect, in which oxygen continues to be consumed in the tissue through cellular respiration and carbon dioxide is produced but not transported away.
  2. Metabolic changes:
    In the case of acidosis that is caused by the metabolism, the so-called metabolic acidosis, a particularly common cause is strong muscular stress. In this case, more acidic lactate is produced from the sugar metabolism, resulting in lactic acidosis.
  3. Type 1 diabetes mellitus:
    At the Type 1 diabetes mellitus, i.e. an absolute lack of insulin, in the event of a deficient insulin substitution, the body can no longer use sugar for energy production. The metabolism helps itself by making use of the fat reserves, acidic ketone bodies are formed as a metabolic product and ketoacidosis results.
  4. Fast:
    The metabolic situation is similar during fasting, no carbohydrates are supplied and the body also falls back on the fat reserves here.
  5. Diarrhea:
    Another, relatively common cause of an acidic metabolic condition is prolonged or severe diarrhea (diarrhea). With this, more basic substances are excreted from the small intestine and consequently the body becomes more acidic.

For more detailed information, see: Acidosis - Symptoms, Causes and Therapy

How can I lower the pH level in my blood myself?

If the blood pH is increased, the body also tries to compensate for this. If the increase results from hyperventilation, metabolic processes are activated in the body that counteract this increase.

The main mechanism of this compensation lies in the increased excretion of bicarbonate, the salt of carbonic acid. Carbonic acid is created when carbon dioxide is dissolved in water and, as the name suggests, is acidic. The salt of an acid is basic and the increased excretion of a base leads to a decrease in the pH value.

In summary, it can be said that a healthy person does not need to lower or increase their pH. The body's regulating mechanisms ensure a constant pH value.

In the case of illnesses and derailments that are accompanied by a threatening change in the pH value, therapy must be carried out to correct the pH value in order to maintain the functions of the body.

What are the long-term consequences of a permanently low pH value?

A reduced pH value in the blood promotes the release of oxygen to the tissue, but at the same time it is bound to the blood more poorly in the lungs and this can result in an undersupply again.

A reduced pH leads to an increase in the potassium concentration in the blood; this change can also lead to cardiac arrhythmias. An increase in potassium also leads to muscle weakness, but through permanent excitation of the muscles. In the long term, this can lead to paralysis.

Does the pH fluctuate during the day?

During the course of the day, too, the body tries to keep the pH value of the blood constant so that, for example, no significant pH value fluctuations can be detected in the blood after meals.

On the other hand, the pH value in the urine behaves differently, which can fluctuate greatly during the day. Urine tends to be acidic in the morning, while it rises after meals.

Does pH differ between the sexes?

Basically, the pH value in the blood differs only slightly between the sexes. However, men have on average a higher muscle mass and under certain circumstances a higher amount of lactate is produced during physical exertion. The consequence is a greater drop in pH.

Which pH levels in the blood can be life-threatening?

While slight derailments in the pH value may cause no or only slight discomfort, values ​​that exceed or fall below a certain value are life-threatening.

If the pH drops to values ​​below 7.1, one speaks of life-threatening acidosis. If the pH value exceeds 7.6, alkalosis is life-threatening.

How does the pH value in the blood change during pregnancy?

Even during pregnancy, the organism needs a constant pH value between 7.35 and 7.45.

While the pH in the blood must be kept constant, larger pH fluctuations can occur in other body fluids. For example, excessive personal hygiene can lead to an increase in the pH value of the naturally acidic vagina and thus promote infections.

The following topic could also be of interest to you: pH of the vagina

How does the pH change in cancer?

Cancer is a disease that greatly increases the body's energy expenditure. The rapidly dividing cancer cells require a lot of energy. As a result, people suffering from cancer often suffer from malnutrition.

Cancer diseases and the highly stressful therapeutic measures lead to pain and nausea, which further intensifies malnutrition.

Due to this deficiency, the body switches the metabolism to starvation mode, which leads to ketoacidosis, similar to fasting.

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