Tap to Read ➤

pH Levels in the Body

Dr. Sumaiya Khan
The pH level is maintained by every organ and every cell of the body. Read on to know of its levels in the body in different organs and what happens if it increases or decreases.
Every reaction in the body that is a part of our metabolism is mostly a chemical reaction. These chemical reactions are carried out by small protein molecules known as enzymes, which are responsible for bringing about various reactions, like hydrolysis of fats and break down of large carbohydrate and protein molecules.
However, these enzymes require a specific environment to function properly. This environment is primarily the pH at which the enzymes function. The pH levels in the body vary from organ to organ. Details about the same are given below.

pH Levels in the Human Body

In general, the pH level of the blood is slightly alkaline, around 7.4. The pH of blood is very narrow and usually does not go anywhere beyond 7.45, with the ideal being 7.4. Basically, when an individual is healthy, his/her body pH is balanced between an alkaline and an acidic environment.
However, the pH for various parts of the digestive system vary according to the organ and the need of the enzymes. These are enlisted here:
  • Mouth:
    The pH of saliva is usually slightly acidic to neutral, hovering around 6.5 to 7.5, so as to ensure proper functioning of the enzyme salivary amylase or ptyalin.
  • Stomach:
    The pH of stomach is very low and highly acidic, being around 4-6 in the upper stomach and around 1.5-3 in the lower stomach. This low pH is due to the hydrochloric acid present in this organ, which helps to ensure proper functioning of the enzyme pepsin.
  • Intestines:
  • The pH of the intestines is usually slightly acidic to neutral, being around 5-7, as this is the pH at which the enzymes in this region functions.

Decrease in pH

Acidosis is a condition where there is low pH level in the body, due to which the blood becomes acidic. This happens due to the hydronium ion concentration increasing in the blood.
So, when its value in blood falls below 7.35, the acidosis symptoms start showing up. This usually happens when there is less oxygen and an increase in carbon dioxide content in the blood. There are different kinds of acidosis, like respiratory, metabolic, diabetic, and lactic. Thus, the symptoms and treatment for each of these vary accordingly.

Increase in pH

Alkalosis is a condition where the pH levels increase to more than 7.45, usually due to a decrease in the hydrogen ion concentration. There are primarily two types of alkalosis, viz., respiratory and metabolic. Alkalosis of the respiratory type is usually due to hyperventilation, because of which there is a loss of carbon dioxide.
Metabolic alkalosis is due to excessive vomiting, leading to loss of hydrochloric acid from the stomach. One of the main dangers associated with alkalosis is hypokalemia. Thus, the symptoms include muscle weakness, cramping, and constipation. The treatment for this condition varies depending on the type of alkalosis.
This was all about the normal pH ranges in the human body and what happens when there is an increase or a decrease in it. Not only is the pH effect on enzymes important for their functioning, but its value in the body, and especially the blood, needs to be maintained for proper functioning of each and every cell.
Also, balancing pH levels is done by each and every cell of the body so as to establish homeostasis. Maintaining the pH levels is of utmost importance, as acidosis and alkalosis are both very dangerous conditions that could eventually lead to death.