Daily Habits That Help and Hurt Your Liver

Lactate dehydrogenase, commonly known as LDH, is an enzyme found in nearly all body tissues. It plays a crucial role in the process of converting sugar into energy for cells. When tissues are damaged or cells break down, LDH is released into the bloodstream, making it a valuable marker for detecting tissue damage. The LDH blood test measures the amount of this enzyme in the blood and can help healthcare providers identify various conditions affecting different organs and tissues.

The LDH test is typically ordered when a doctor suspects tissue damage or disease in organs such as the heart, liver, kidneys, lungs, or blood cells. Common reasons for testing include investigating unexplained fatigue, weakness, or anemia, monitoring certain cancers like lymphoma or leukemia, evaluating possible heart attack or stroke, checking for liver disease, or assessing muscle damage. Since LDH is present in many different tissues throughout the body, elevated levels indicate that damage has occurred somewhere, though the test alone cannot pinpoint the exact location.

Preparation for an LDH test is usually minimal. In most cases, no special preparation is required, and patients can eat and drink normally before the test. However, certain medications and supplements can affect LDH levels, so it is important to inform your healthcare provider about all medications you are taking. The test itself involves a simple blood draw from a vein, typically in the arm, which takes only a few minutes. Some people may experience slight bruising or soreness at the puncture site, but serious complications are rare.

Normal LDH levels generally range from 140 to 280 units per liter, though this can vary slightly depending on the laboratory and testing method used. Elevated LDH levels can indicate various conditions including heart attack, liver disease, certain types of anemia, muscle injury, bone fractures, certain cancers, lung disease, or infections. Very high levels often suggest more severe tissue damage. However, strenuous exercise can also temporarily raise LDH levels. Lower than normal LDH levels are uncommon but may occur with certain genetic conditions or excessive vitamin intake.

If your LDH test results are abnormal, your healthcare provider will likely order additional tests to determine the specific cause and location of tissue damage. These may include LDH isoenzyme tests, which can help identify which organ is affected, along with other blood tests, imaging studies, or biopsies. The LDH test is most useful when combined with other diagnostic information and should always be interpreted by a qualified healthcare professional in the context of your overall health status and symptoms.