Some sufferers are fortunate to maintain a higher that normal HbF production throughout their lives which improves their condition. Many episodes of sickling occur spontaneously although certain factors may increase the risk. Hypothermia and dehydration are also important causing venous stasis and hypoxia via vasoconstriction. Clinical Features Patients with sickle trait are usually fit and healthy. However patients with sickle cell disease will usually demonstrate multiple organ damage through repeated veno-occlusive episodes superimposed on a history of poor development and failure to thrive.
Blood transfusion is often essential.
Damage to the spleen with increased susceptibility to infections occurs with age. Repeated episodes can lead to compromised lung function, pulmonary hypertension and respiratory failure. The relative hypoxia and hyperosmolarity of the renal medulla creates an environment for sickling in the vasa recta. The long Loops of Henle are destroyed causing renal failure as the kidney loses its ability to concentrate urine. Haematuria is also a complicating feature.