Alkaline Vs. Acidic pH Levels

One of the most important aspects of human physiology is homeostasis, which is the drive to keep the internal makeup of the body in a stable state. Part of this involves controlling the relative amounts of acidic and alkaline chemicals, also known as bases, in the body. Maintaining the right balance of acids and bases in the body is critical for cells and proteins to function properly.

Blood and pH

The balance of acids and bases in the blood is tightly regulated. The balance of these chemicals is usually measured on the pH scale. Acidic compounds have a low pH and alkaline compounds have a high pH; neutral pH is defined as 7. The blood normally has a pH of between 7.35 and 7.45. If the pH of your blood drops below this, you have acidosis, whereas an abnormally high blood pH is termed alkalosis.


Because the blood needs to be kept at such a narrow pH range, the body has a number of ways to control pH. Because carbon dioxide is mildly acidic, the pH of the blood can be controlled by the lungs, the Merck Manual explains. The kidneys can also control the pH of the blood by increasing or decreasing the amount of acid excreted in the urine. Finally, the body uses buffers, which are chemicals that help prevent any sudden changes in pH.


Acidosis is caused by too much acid accumulating in the blood. One kind of acidosis, known as respiratory acidosis, is caused by too much carbon dioxide building up in the blood as a result of slowed or impaired breathing. Acidosis can also be caused by the ingestion of acidic substances, problems with metabolism or kidney dysfunction. These types of acidosis are classified as metabolic acidosis. Acidosis can cause nausea, vomiting, drowsiness and confusion.


Alkalosis is the result of the blood's pH getting too high. Respiratory alkalosis is caused by hyperventilation, which can be caused by anxiety, the Merck Manual reports. Metabolic alkalosis is most commonly caused by the loss of large quantities of acid from the body, which can occur as a result of frequent vomiting. Alkalosis can also be caused by the ingestion of large quantities of basic substances, such as sodium bicarbonate. Alkalosis typically causes muscle twitching, irritability and muscle cramps.

Food Effects

One new nutritional plan is the acid/alkaline balance diet. The idea behind this eating plan is that most people have chronic acidosis as a result of consuming too much acid-producing food 1. Although the body is able to counteract the effects of this acid, the acid-generating foods can stress the body and deplete some of its minerals, says Dr. Ben Kim, chiropractor and acupuncturist in Ontario, Canada 1.