LDH (lactate dehydrogenase) tests measure the amount of the LDH enzyme in the blood, which rises when cells are damaged or dying. In cancer, higher LDH levels often reflect increased tumor cell turnover or tissue injury and can correlate with greater tumor burden, more aggressive disease, and worse prognosis in cancers such as lymphoma, melanoma, certain leukemias, and germ cell tumors.

LDH is nonspecific—many noncancer conditions (hemolysis, liver disease, heart attack, infection, muscle injury) also elevate LDH—so the test cannot diagnose cancer alone but is used alongside imaging, pathology, and other markers to help assess disease activity, prognosis, and response to treatment.

LDH is measured from a blood sample, most commonly a standard venous draw (needle from a vein in the arm) collected into the lab’s serum or plasma tube; the laboratory separates the blood components and measures LDH enzyme activity in the serum or plasma.

No special preparation is usually needed, but the sample must be handled promptly and without hemolysis (ruptured red cells) because hemolysis artificially raises LDH. Finger‑stick or point‑of‑care capillary tests exist in some settings but are less common than routine venous sampling for accurate clinical monitoring.

Lactate dehydrogenase (LDH) is an enzyme released when cells are damaged; a higher-than-normal LDH level can be a nonspecific sign of tissue injury and is seen with many conditions including infections, liver disease, hemolysis, and certain cancers. In oncology, persistently high or rising LDH can sometimes reflect greater tumor burden or more aggressive disease and is used in some cancers as part of prognosis or monitoring, but it cannot by itself diagnose cancer.

A single LDH result must be interpreted with your lab’s reference range, the testing method, and other clinical information—trends over time are often more informative than one value. Because many noncancer factors can raise LDH (sample hemolysis, recent exercise, medications, other illnesses), discuss your personal LDH result and next steps with your healthcare provider who can correlate it with symptoms, exams, and other tests.

LDH (lactate dehydrogenase) is a non‑specific marker of cell damage: levels can be raised by many causes (hemolysis, liver disease, infection, inflammation and others) as well as by cancer. Because of that low specificity, a single elevated LDH test cannot diagnose cancer and a normal LDH does not rule it out.

Where LDH is most useful is as an adjunctive marker: in some cancers (for example certain lymphomas, melanoma and germ‑cell tumors) it can correlate with tumor burden, prognosis and treatment response, and serial measurements are more informative than a one‑off value. LDH results should always be interpreted alongside clinical assessment, imaging and disease‑specific tumor markers.

How often LDH should be tested depends on your cancer type, stage and treatment plan — LDH is a nonspecific marker used alongside other tests. Common practice is to obtain a baseline at diagnosis, then test serially to monitor treatment response (often before or at regular intervals during each treatment cycle or clinic visit) and to check for progression if symptoms change.

During follow‑up many clinicians measure LDH every 2–4 months in the first 1–2 years, then spacing testing to about every 6–12 months if stable, but schedules vary widely. Always follow your oncologist’s individualized plan and remember an LDH result is not diagnostic by itself — significant changes usually trigger further evaluation rather than being acted on in isolation.

No — LDH test results are not diagnostic. LDH is a common enzyme found throughout the body, and abnormal levels can reflect many causes (tissue damage, hemolysis, inflammation, or malignancy), so LDH values highlight patterns of imbalance or resilience—not medical diagnoses.

LDH results must be interpreted alongside symptoms, medical history, physical exam findings, imaging, pathology, and other laboratory or biomarker data by a qualified clinician; abnormal LDH should prompt further evaluation rather than serving as a stand‑alone diagnosis of cancer.

If your LDH (lactate dehydrogenase) is high, the only reliable way to lower it is to address the underlying cause — LDH is a nonspecific marker of tissue damage, inflammation, hemolysis, liver disease, muscle injury and in some cancers reflects tumor burden or aggressiveness. Work with your physician or oncologist to follow recommended cancer treatment (surgery, chemotherapy, radiation or targeted agents) or to treat other causes (control infections, manage liver disease, correct hemolysis, stop offending drugs). Short-term measures that can help reduce transient elevations include good hydration, treating concurrent infections or inflammation, avoiding heavy exercise before retesting, and limiting alcohol intake.

Expect the timing of improvement to depend on the cause and treatment — levels can normalize in days to weeks for reversible causes or fall more slowly as cancer responds to therapy. LDH should be interpreted and trended by your care team alongside imaging and other tests; do not try to "self‑treat" based on LDH alone and contact your clinician for individualized management and follow‑up testing.