What Does an LDH Level of 398 Indicate?
An LDH level of 398 U/L (assuming normal range approximately 313-618 U/L) is within or just slightly above the normal range and is generally not clinically significant on its own, but requires clinical context to interpret properly.
Interpretation of This Specific Value
- Your LDH of 398 falls within the typical normal range (313-618 U/L), representing less than 1.5 times the upper limit of normal 1
- Mild LDH elevations (<5× upper limit normal) are most commonly associated with benign causes 1
- This level does not warrant aggressive investigation for malignancy unless accompanied by other clinical findings 2
Clinical Context Matters
The diagnostic value of LDH depends entirely on your clinical presentation and should be interpreted alongside other findings 1. This level could represent:
Benign Causes (Most Likely)
- Strenuous exercise can temporarily elevate LDH due to muscle damage 1
- Hemolysis of the blood sample itself can falsely elevate LDH 1
- Liver disease, kidney disease, or recent infections 1
- Myocardial conditions or muscle injury 1
When to Investigate Further
You should pursue additional workup if you have:
- Known or suspected malignancy - LDH serves as a prognostic marker in testicular cancer, osteosarcoma, melanoma, and lymphomas 1, 2
- Unexplained symptoms such as weight loss, night sweats, or lymphadenopathy 3
- Other abnormal laboratory values accompanying the LDH elevation 2
- Progressive elevation on serial measurements 2
Prognostic Significance in Specific Cancers
If you have a known malignancy, this near-normal LDH is generally favorable:
- In testicular cancer, good prognosis requires LDH <2.5× upper limit of normal 1
- In osteosarcoma, elevated LDH (significantly above normal) correlates with metastatic disease and 5-year survival of 39.5% versus 60% for normal values 3, 1
- In lymphoma, rising LDH may indicate transformation, particularly if a single site grows disproportionately or new B symptoms develop 3
Recommended Approach
Do not pursue extensive investigation based solely on this LDH level 2. Instead:
- Repeat the test if hemolysis is suspected (sample handling issue) 1
- Correlate with your clinical symptoms and other laboratory findings 1
- If you have no symptoms and no other abnormalities, this level requires no further action 2
- If you have concerning symptoms, pursue targeted investigation based on those specific findings rather than the LDH alone 2
Key Pitfall to Avoid
Never treat or extensively investigate based on LDH elevation alone without identifying an underlying cause 2. Very high LDH (>10× normal, or >6000 U/L) carries prognostic significance with mortality rates exceeding 50%, but your level of 398 does not approach this threshold 4, 5.