When is a blood test recommended for G6PD deficiency?

G6PD is an enzyme that helps red blood cells handle oxidative stress. Deficiency can make these cells more vulnerable to breaking down after particular medicines, infections, or foods. A clinician may consider testing if you have jaundice, dark urine, unusual paleness, tiredness, or breathlessness during an episode of suspected haemolysis.

Testing may also be discussed when a close relative has the deficiency, when a previous reaction followed a medicine, or before treatment where G6PD status affects prescribing. The result is interpreted with your recent illness and blood counts.

Give your clinician a complete medicine and supplement list and describe any previous reaction, infection, or food exposure. Do not delay urgent treatment for a serious illness while waiting for a test, and do not stop a prescribed medicine without medical advice.

If testing follows red-cell breakdown, timing can matter because recently produced red cells may affect the enzyme result. Your clinician may recommend repeat testing after recovery when the first result does not fit the clinical picture. Keep a confirmed diagnosis available for future prescribing.

Seek urgent medical care for yellowing of the eyes or skin, cola-coloured urine, severe weakness, breathlessness, a fast heartbeat, confusion, or fainting, particularly after an infection or new medicine. These can signal significant red-cell breakdown and need assessment without waiting for a routine appointment.

Why is G6PD testing appropriate for me? Could recent haemolysis affect the result? Which medicines or foods should I discuss before using them? Do family members need advice or testing?