Lactate Dehydrogenase (LDH) Test – Purpose & Risks Explained

Lactate Dehydrogenase (LDH) is a type of protein boosting the energy level in your body. Tissues in your heart, kidneys, brain, and lungs mainly constitute LDH. A LDH test has the role of measuring the level of LDH in your body. Doctors might ask you to undertake this test if they suspect damages in your tissues or enzymes.

Do you wish to learn more about the LDH test? Then, read till the end of this article to determine the causes, types, and treatments of LDH issues.

The LDH test helps check the LDH levels in your blood. In other cases, the doctors can also measure LDH levels in your urine or cerebrospinal fluid (CSF).

Lactate dehydrogenase is an enzyme essential for your body, particularly while turning sugar into energy for your cells. It is present in multiple organs and tissues across your body. When your cells are damaged by illness or injury, LDH releases into your bloodstream, causing an increase in your blood LDH level.

Your doctor might ask you to do a test for the following reasons.

• Checking for any tissue damages
• Monitoring infections and other health conditions, including hemolytic or megaloblastic anaemia, kidney and liver diseases
• Evaluating cancer treatment in the patients
• Finding the cause of fluid build ups such as injury or inflammation 
• Determining if you have bacterial or viral meningitis 
  

There are usually about five different forms of Lactate Dehydrogenase, also called isoenzymes. Health researchers have differentiated these based on slight structural differences. These are as follows.

• LDH-1: Found in heart and red blood cells
• LDH-2: Found in heart and red blood cells
• LDH-3: Found in lymph tissue, platelets, lungs, pancreas
• LDH-4: Found in the liver and skeletal muscle
• LDH-5: Found in the liver and skeletal muscle

Now that you know what an LDH test means, you might be curious about its procedure. Usually to check for LDH in blood tests, doctors will draw blood from your body by inserting a needle in your veins. However, doctors will insert a lumbar puncture or spinal tap on your lower back if the test is done for cerebrospinal fluid. In the case of infants, a sharp tool called a lancet is used to take a blood sample. The doctor will ask you all about your medical history, including the medicines, supplements, herbs, or vitamins that you are currently taking before conducting this test.

The LDH test is similar to most of the blood tests. So, the risks are usually limited. However, in some cases, patients have faced mild bleeding, soreness, and bruising in the injection site. Few of them have also suffered from infection. Moreover, if you undergo a lumbar puncture, you might face headaches, bleeding, and numbness. However, these are hardly severe issues and can be resolved with simple medication.

Now that you know what the LDH test is, you must be curious about the causes of high LDH. Usually, high LDH levels in your blood can harm your health. Doctors are likely to recommend various treatment procedures in such conditions. Now, the question that arises here is, “what are the causes of high LDH levels?”. Different health conditions can trigger the growth of Lactate Dehydrogenase enzymes in the blood, which includes the following -

• Heart attack
• Liver diseases
• Anaemia
• Muscle trauma and bone fractures
• Cancers and their treatment
• Infections such as meningitis, encephalitis, and HIV
• Blood flow deficiency
• Tissue death

A high LDH level in an LDH test primarily indicates tissue damage in your body. If a patient suffers from high LDH because of more than one isoenzymes, it implies more than one cause of damage in tissue (like a pneumonia patient having a heart attack). On the other hand, an extremely high level of Lactate Dehydrogenase in blood might represent a multi-organ failure or other serious health complications.

High LDH results in different health conditions, including anaemia, heart and liver diseases, bone fractures, cancer, etc. The treatment procedure will be different for patients depending on their health condition because of high LDH. As LDH is spread across numerous tissues, additional diagnosis is required to identify the areas of tissue damage. Once the doctors determine the health condition triggering high LDH, they will start your treatment accordingly.

Now that you know what LDH in a blood test is, you realise the risks arising from high levels of this enzyme in the blood. You can try to maintain an average LDH level with the help of the following activities.

• Include vitamin C-rich food items in your diet (citrus fruits, broccoli, Brussels sprouts, peppers etc.).
• Limit your alcohol consumption.
• Reduce specific drug consumptions, including anaesthetics, aspirin, narcotics, and procainamide.

As you can see, conducting an LDH test helps determine the LDH level in your blood and start immediate treatment if the levels are high. High LDH levels can be harmful, resulting in various life-threatening diseases. The test is quick and straightforward, and most doctors prefer to do it before undertaking any detailed diagnosis.