Laboratory test for G6PD deficiency

G6PD helps red blood cells cope with certain medicines, infections, and foods. Low activity can allow red cells to break down quickly, causing haemolytic anaemia. Testing may follow jaundice, unusual tiredness, pale skin, or dark urine, or a family pattern. Results can be harder to interpret during or soon after red-cell breakdown because younger cells may show more enzyme activity. Repeat testing or specialist advice may be needed.

Tell the clinician about recent illness, transfusion, medicines, supplements, and family history. Do not stop prescribed medicine without advice; ask which substances should be checked if deficiency is confirmed. Keep the result available for future clinicians and pharmacists. A Blood Test page explains general sample collection. A diagnosis guides safer choices, but does not mean every exposure will cause a reaction.

Seek urgent help for sudden dark urine, yellow eyes, severe weakness, breathlessness, fainting, chest discomfort, or rapidly worsening pale skin, especially after a new medicine or infection. These symptoms can indicate rapid red-cell breakdown and anaemia. A baby with marked jaundice, poor feeding, unusual sleepiness, or difficulty waking needs immediate assessment.

Was enzyme activity low, borderline, or within the expected range? Could illness or transfusion have affected the result? Should testing be repeated? Which medicines, foods, or chemicals should I discuss before using? Should relatives be tested?