What should you know about a high HGB blood test?

Haemoglobin is the oxygen-carrying protein inside red blood cells. A raised result can reflect a concentrated blood sample after fluid loss, or the body's response to reduced oxygen availability. Smoking, living at altitude, lung disease, sleep-related breathing problems, and some heart conditions may be relevant. Less commonly, a bone-marrow disorder can increase red-cell production.

The number should be read with the haematocrit, red-cell count, symptoms, oxygen level, medical history, and the laboratory range. One unexpected result does not establish the cause. A repeat sample may be useful if dehydration, recent illness, or testing circumstances could have influenced it.

Arrange a non-urgent review to discuss the report, especially if the finding persists or you have headaches, blurred vision, facial flushing, itching after a warm shower, or unusual tiredness. Tell the clinician about smoking, altitude travel, breathing symptoms, fluid loss, medicines, and supplements. Do not donate blood or change prescribed treatment as a way to correct the result without medical advice.

The clinician may repeat the full blood count and review oxygen levels, kidney and lung health, sleep symptoms, and other causes before deciding whether specialist assessment is needed.

Get emergency help for sudden weakness, trouble speaking, severe chest pain, severe breathlessness, a new vision problem, or a painful swollen leg. These may signal a serious circulation problem and require urgent assessment. Seek prompt medical advice for persistent severe headache, unexplained bleeding, or rapidly worsening symptoms.

Ask whether the result could reflect dehydration or reduced oxygen, whether it should be repeated, and how the other blood-count values change its meaning. Ask which symptoms require urgent help and whether smoking, sleep, lung, heart, or kidney issues should be checked.