Your potassium is 5.8 mmol/L — above the lab's threshold. Your doctor calls and says "go to the ER." But you feel fine, and you know you did a hard workout yesterday. Is this a real emergency or a pre-analytical error?
Every athlete who submits blood work to GearCheck eventually encounters an abnormal result that does not make sense. You feel fine, your training is going well, and the result contradicts everything you know about your health. In many cases, the result is correct and needs attention. But in a surprising number of cases — our data suggests 15-20% of flagged results — the abnormality is caused by how the blood was drawn, handled, or processed, not by an actual health problem.
Learning to distinguish lab error from real signal is one of the most valuable skills you can develop as someone who regularly tests blood. Here is how to tell the difference.
Pre-analytical errors happen before the sample is analyzed. They occur during collection, handling, transport, or storage. In athletes, three specific errors account for the majority of false abnormal results:
Hemolysis: The Athlete's #1 Lab Error
Hemolysis occurs when red blood cells rupture during the draw, releasing their contents into the plasma. This is more common in athletes because muscular arms have deeper, more resilient veins that are harder to puncture cleanly. The phlebotomist may need to "dig" to find the vein, causing mechanical damage to red cells as they pass through a narrow or partially occluded needle.
Hemolyzed samples show a characteristic pattern: elevated LDH (often > 300), high potassium (from ruptured RBCs), and elevated AST (also released from red cells). If you see this triad in an otherwise healthy person — normal kidney function, no symptoms, no recent training — hemolysis is the most likely explanation.
The Hemolysis Triad
Prolonged Tourniquet
A tourniquet left on for more than one minute causes blood to concentrate in the limb. Fluid shifts out of the veins into the surrounding tissue, concentrating the blood cells and large molecules left behind. This affects: potassium (can rise 0.3-0.5 mmol/L), total protein and albumin (up 5-10%), and hematocrit (up 2-4%). The effect is proportional to tourniquet time — every 30 seconds past the first minute adds measurable artifact.
Fasting Violations
A non-fasted draw is the most common preventable error. Triglycerides can spike 200-300% after a meal, making LDL calculations unreliable. Glucose reflects your last meal, not your metabolic health. Even ALT can be mildly elevated after a high-fat meal. If your triglycerides are surprisingly high but your LDL is normal and your HDL is good, a fasting violation is the most likely cause.
Lab Error vs. Real Signal: How to Tell
| Marker | Likely Lab Error | Likely Real Signal |
|---|---|---|
| Pattern | Single marker out of range, everything else normal | Multiple related markers form a consistent pattern |
| Potassium | High K + high LDH + high AST = hemolysis | High K + low GFR + high creatinine = kidney issue |
| AST/ALT | Isolated AST elevation with normal ALT/GGT | Elevated AST + ALT + GGT = liver origin |
| Lipids | Very high TG + normal LDL + non-fasted draw | High LDL + low HDL + high ApoB = genuine dyslipidemia |
| Timing | Drawn after training (elevated CK, AST, creatinine) | Consistent elevation despite 72h rest |
| Symptoms | No symptoms, feel normal | Symptoms match the abnormal marker |
| History | First time elevated, never been high before | Trending up over multiple draws |
The decision to redraw depends on the severity of the abnormality and the supporting evidence. Use this framework:
- Redraw if: a single marker is mildly to moderately elevated (less than 2x the upper reference limit), no other markers support it, you have no symptoms, and the result does not match your history. The most common example: isolated AST of 80 U/L with normal ALT, GGT, and CK. Redraw with proper rest and a clean draw technique.
- Redraw if: the lab report flags the sample for hemolysis, lipemia, or icterus. These are visible indicators that the sample quality was compromised. Do not accept results from a hemolyzed sample — they are unreliable and should be rejected by the lab before they are even reported.
- Act immediately if: potassium > 6.0 mmol/L, hemoglobin < 7 g/dL, platelets < 20,000, or any value the lab marks as "critical." Even if lab error is possible, critical values require immediate medical evaluation. You can sort out whether it was an error later.
- Act if: the same marker is abnormal across multiple draws, the pattern is consistent with your protocol (e.g., HDL is low on an AAS cycle — expected, not an error), or you have symptoms that match the lab abnormality.
The Redraw Protocol
While lab errors are common, real problems are also common in the AAS-using population. The key is not to dismiss every abnormal result as a lab error — it is to evaluate each result in context. You should act on a result when:
- Multiple independent markers point to the same problem (e.g., elevated creatinine + low eGFR + elevated cystatin C = real kidney concern)
- The same marker is consistently abnormal across multiple draws under optimal conditions
- The abnormality matches known pharmacological effects of your compounds (e.g., low HDL on orals is expected, not an error)
- You have clinical symptoms that align with the lab finding
- The value exceeds critical thresholds — no amount of "it might be an error" excuses ignoring a critical lab value