Lactate Dehydrogenase (LDH)

What is Lactate Dehydrogenase (LDH) Test?

The Lactate Dehydrogenase test evaluates the amount of lactate dehydrogenase in your blood or other bodily fluids. LDH is a vital enzyme that plays a key role in the process of cellular respiration, which is responsible for converting glucose into energy for your cells. LDH is present in nearly all tissues of your body, but its highest concentrations are found in the liver, muscles, red blood cells, and kidneys. When new cells are formed in tissues, the older or dead cells are eliminated by your body's natural process, which causes LDH to be released into your bloodstream or other bodily fluids. As a result, it is common to have some LDH in your fluid or blood sample at all times.

The LDH test plays a crucial role in detecting and evaluating the extent and position of tissue damage within the body. It is also utilized to monitor the advancement of specific illnesses.

What is the Purpose of Lactate Dehydrogenase (LDH) Test? 

The Lactate Dehydrogenase test is particularly useful in identifying the extent of damage to the body's tissues. Furthermore, doctors may also use LDH testing to monitor the progression of megaloblastic anemias, liver disease, and kidney disease. This allows the doctors to make informed decisions regarding the patient's ongoing care. The Lactate Dehydrogenase test can also be used to evaluate certain cancers. You may have to undergo regular Lactate Dehydrogenase tests to determine if you have viral or bacterial meningitis. 

What does the Lactate Dehydrogenase (LDH) Test Diagnose? 

An LDH test is employed by healthcare providers to diagnose and monitor various health conditions. Your healthcare provider may order this test: 

• To detect if you have any kind of tissue damage.
• To check if you have certain types of infections.
• To assess the severity of cancer

Why Do You Need a Lactate Dehydrogenase (LDH) Test? 

You may need a Lactate Dehydrogenase (LDH) test if you have symptoms of tissue damage. The doctor may also order this test if you're being treated for cancer. Doctors typically check for LDH levels in the blood, although they may also check for LDH levels in urine or cerebrospinal fluid in certain situations. 

Preparation and procedure required for Lactate Dehydrogenase (LDH) Test 

It's important to note that certain medications and substances can affect the accuracy of LDH tests. For example, large amounts of vitamin C can lower LDH levels, while alcohol, anesthetics, aspirin, narcotics, and procainamide can increase LDH levels. Strenuous exercise can also temporarily increase LDH levels. It's recommended to consult with a doctor about any medications or activities to avoid prior to the test to ensure accurate results. 

When testing LDH levels in adults, a technician will usually use a needle to draw blood from a vein in the inner elbow or back of the hand. Prior to this, the technician will clean the area with an antiseptic and apply an elastic band around the upper arm to increase blood flow to the vein. After gently inserting the needle, blood will flow into a tube attached to it. Once the tube is full, the technician will remove the elastic band and needle and apply a bandage to the puncture site. 

In infants, a lancet may be used to draw a small amount of blood, which will get collected in a tube. You might experience little discomfort during and after the procedure. 

Understanding the Lactate Dehydrogenase (LDH) Test results 

The levels of LDH can differ depending on the laboratory and age of the person. Infants and young children typically have significantly higher LDH levels that are considered normal, while older children and adults have lower LDH levels. In general, the normal level for LDH levels in the blood is as follows:

High LDH Levels 

Elevated levels of LDH in the blood suggest the presence of tissue damage, but it cannot pinpoint the exact cause or location of the damage. Multiple isoenzymes of LDH may indicate more than one source of tissue damage. For instance, pneumonia and heart attack could both raise LDH levels. Extremely high levels of LDH could indicate multiple organ failure or severe illness.

Because LDH is present in various tissues, it is impossible to determine the tissue damage's specific cause and location solely by measuring LDH levels. A complete diagnosis necessitates additional tests, imaging, and measuring LDH levels. Elevated LDH-4 and LDH-5 levels may suggest liver or muscle damage, but the liver disease can only be confirmed with a full liver panel.

Low LDH Levels

LDH deficiency has an impact on the body's ability to break down sugar to produce energy in cells, specifically in muscle cells. It is rare for an individual to have low levels of LDH.

There are two types of genetic mutations that result in low levels of LDH. Those with the first type are likely to experience exhaustion and muscle discomfort, particularly during physical activity. In contrast, those with the second type may not exhibit any symptoms at all. Additionally, individuals may have low levels of LDH if they have consumed excessive amounts of ascorbic acid, also known as vitamin C.