But elevated haemoglobin levels still leave them at risk for mountain sickness with old age.

The genes are associated not only with decreased haemoglobin levels, but also in regulating energy metabolism.

Haemolytic crises are acute accelerated drops in haemoglobin level.

Blood tests revealed Louise's haemoglobin level was down and doctors referred her to the local hospital.

Your haemoglobin level should stay above 11gm (75 per cent).

At every donation haemoglobin levels are checked and donors complete an in depth health and lifestyle questionnaire.

The body automatically detects the lower haemoglobin level, and compensatory mechanisms start up.

In extreme cases, patients have survived with a haemoglobin level of 2 g/dl, about 1/7 the norm, although levels this low are very dangerous.

The other important development has been the glycosylated haemoglobin level.

It should include assessment and provide feedback on progress with glycosylated haemoglobin levels.