Lactate Dehyderogenase (LDH) Ascitic Fluid (1ml)

A high LDH level in ascitic (peritoneal) fluid is generally considered when fluid LDH exceeds about 200 IU/L or the ascites-to-serum LDH ratio is >0.6. Such elevations suggest exudative processes — infection (including bacterial peritonitis), malignancy, or significant inflammation — rather than simple cirrhotic transudate, and prompt further diagnostic workup (cultures, cytology, imaging).

If LDH (lactate dehydrogenase) is high, it indicates tissue damage or cell breakdown but is nonspecific. Causes include hemolysis, liver disease, heart attack, muscle injury, infections, or some cancers. Your clinician will repeat tests, review symptoms and other labs (e.g., AST, ALT, CK, troponin, bilirubin) and may order imaging or targeted tests. Treatment addresses the underlying cause; follow up promptly with your provider.

Normal LDH in body fluids varies by site. Pleural and peritoneal (ascitic) fluid LDH is typically low—generally <200 U/L or below two‑thirds of the upper serum LDH limit. Cerebrospinal fluid LDH is much lower, usually under ~20 U/L. Serum LDH is about 140–280 U/L; fluid interpretation commonly compares fluid LDH to serum (e.g., Light’s criteria for pleural effusions).

There’s no single LDH cutoff that proves lymphoma. Any value above your laboratory’s upper limit is a nonspecific red flag; clinicians use elevated LDH as a prognostic marker. Levels roughly two times the upper limit (for example >500 U/L when the normal upper limit is ~250 U/L) often indicate high tumor burden or more aggressive disease and prompt further investigation.

Ascites is a hallmark of decompensated liver disease—usually advanced cirrhosis due to portal hypertension and impaired liver function. It marks progression from compensated to decompensated cirrhosis and typically reflects more severe stages (worse Child‑Pugh and higher MELD scores). Its appearance requires prompt medical assessment and management to address complications and underlying liver failure.

Malignant ascites causes progressive abdominal distension with a tense, fluid-filled belly. On exam there is shifting dullness and a positive fluid wave. The fluid often appears straw‑colored, cloudy, blood‑tinged or milky (chylous) depending on tumor type. Patients commonly have early satiety, breathlessness and weight loss; imaging may show peritoneal nodules or omental caking indicating cancer spread.