What It Means and How To Maintain It

Maintaining a pH balance helps your body self-regulate its acid-base levels and perform biological functions that keep you alive. In chemistry, a pH scale measures how acidic or alkaline (basic) something is, including the human body.

Your organ systems and body fluids also maintain their own pH to support critical chemical reactions that aid functions, metabolism, and hormonal balance. Your body may struggle to maintain those functions and leave you at risk for illness if your pH is imbalanced.

A pH is measured on a scale from zero to 14, in which zero is the most acidic, seven is neutral, and 14 is the most alkaline. pH stands for “potential hydrogen” and measures hydrogen ion concentration. More ions lead to a lower pH (more acidic), while fewer ions mean a higher pH (more alkaline).

In the human body, maintaining a proper pH balance is essential for several bodily functions. Your stomach’s gastric juices (stomach acid) have a pH of 1.5-2 to kill harmful bacteria and break down food during digestion. Your skin has an acidic pH of 4-5.5 to protect against the elements and microbes. 

In the human body, a healthy pH is between 7.35 and 7.45. On average, the body has a pH of 7.4, which is slightly alkaline. Your body needs to stay in this slightly basic pH zone for homeostasis (a stable state) and to function as usual. 

The pH of body parts like the skin and vagina can vary and increase with age due to changing hormones. Your body regulates pH through the airways, lungs, and blood vessels, and the renal (kidneys and bladder) systems. 

The vagina has a moderately acidic pH level between 3.8 and 5 but can vary based on your age, menstrual cycle, and menopause status. It naturally has a balanced environment of bacteria. An acidic pH prevents bacteria overgrowth that causes vaginal infections.

High vaginal pH can allow harmful bacteria to thrive and increase your risk of: 

• Bacterial vaginosis (BV): A bacterial infection that can cause unusual white or gray discharge, fishy odors, itching, and painful urination
• Trichomoniasis: A sexually transmitted infection (STI) caused by a parasite that can cause green or yellow discharge, pain during sex, burning while peeing, and vaginal soreness

The vagina typically balances its pH itself. Some situations can raise or lower vaginal pH, such as:

• Antibiotics: Besides killing harmful bacteria, antibiotics can also kill good bacteria.
• Douching: Cleaning the inside of the vagina with special cleansers removes good bacteria. This creates an abnormal pH.
• Menopause: Postmenopausal people can have a slightly higher pH.
• Menstrual cycle disorders: Hormonal imbalances that cause abnormal menstrual cycles cause an unbalanced vaginal pH. 
• Menstruation: Menstrual blood makes the vagina more alkaline.
• Unprotected sex: Semen can make the vagina more alkaline and increase infection risk.

You will typically have a less acidic pH that allows bacterial overgrowth if you have an unbalanced vaginal pH. Symptoms can include a foul-smelling odor, abnormal vaginal discharge, burning while peeing, and vaginal itching.

You do not need to re-balance your pH unless you have symptoms of BV or another vaginal infection. A healthcare provider will likely prescribe antibiotics to treat an infection linked to a pH imbalance.

For recurring BV, they may suggest using boric acid suppositories with an antibiotic. Antibiotics can alter vaginal pH in the first place, but treating the infection is essential.

Preventative measures against vaginal infections include:

• Avoid douching, harsh soaps, and scented vaginal or period products
• Take probiotics when you take antibiotics
• Use condoms or other barrier methods

When your body’s pH becomes too high or low, your lungs and kidneys usually help it rebalance. You can develop acidosis (a pH less than 7.35) and alkalosis (a pH of more than 7.45) if your body cannot regulate pH.  

Conditions related to an unbalanced pH include: 

• Metabolic acidosis: Your body makes too much acid, or the kidneys cannot remove enough. It can result from kidney disease, dehydration, or aspirin poisoning.
• Metabolic alkalosis: Your blood has too much bicarbonate, which raises pH. The most common cause is kidney disease.
• Respiratory acidosis: Too much carbon dioxide stays in the body due to poor breathing. Causes include lung disease, chest injury, muscle weakness, or sedative overuse.
• Respiratory alkalosis: Breathing too fast lowers carbon dioxide and raises pH. Causes include high altitude, lack of oxygen, liver or lung disease, fever, or aspirin poisoning.

Your body will often try to overcompensate if you develop one of these conditions. It may eliminate too much carbon dioxide as you breathe to cause respiratory alkalosis if you develop metabolic acidosis.

For the average healthy person, pH is not something to worry about. It is not necessary to purchase products or follow strict diets that promise to balance pH. Your kidneys and lungs naturally regulate its pH, so you do not need to balance it yourself. 

Certain conditions can affect your body’s ability to regulate pH. Speak to a healthcare provider if you are female and have symptoms of pH imbalance.

You do not need to worry about actively balancing your pH since your body naturally does it. The average pH is about 7.4, which is slightly alkaline. Your body will naturally regulate this stable state. Some of your organs and body fluids also maintain a different pH to help them function and avoid infections.