People with sickle cell anaemia should be screened for a potentially fatal complication, scientists say.
Sickle cells are named for their distinctive shape
Researchers at the US Institutes of Health found a third of adults with the disease have dangerously high blood pressure in their lungs.
Writing in the New England Journal of Medicine, they say screening could pick up cases of pulmonary hypertension before patients become ill.
Patients could then be given medication to lower their blood pressure.
Sickle cell anaemia is an inherited blood disorder, which largely affects Afro-Caribbean and Asian patients. It is named after the distinctive shape formed by the red blood cells of people with the problem.
The shape is affected because a protein within the cells - haemoglobin - is different to normal. Haemoglobin carries the oxygen which is transported by the blood from the lungs to the body's tissues.
Due to this structural abnormality, sickle cells stick together and link into long fibres, which means they cannot get through small blood vessels as easily as healthy cells.
This can prevent oxygen getting through, leading to damage to organs, or, in some cases, strokes.
Pulmonary hypertension occurs when high blood pressure builds up in the arteries that supply the lungs.
This is caused by the walls of the arteries thickening. This reduces the blood flow through the vessels, and forces the heart to work harder to try to compensate.
Eventually the heart cannot pump enough blood through the lungs to pick up adequate amounts of oxygen. Patients become tired, dizzy and short of breath.
Researchers followed 195 adults with sickle cell anaemia patients for two years.
They used Doppler echocardiography, a test that uses sound-waves to measure the speed of blood flow, to assess the pressure in their pulmonary arteries.
They found 32% of patients had pulmonary hypertension.
A fifth of those died, whereas all but two of the patients without the condition survived.
Dr Griffin Rodgers of the National Institute of Diabetes and Digestive and Kidney Diseases, who also worked on the research, said: "The 'echo' is a test that is reasonably priced, non-invasive and should be recommended screening for adults with sickle cell disease just as the colonoscopy, cholesterol panel, mammogram, and other tests are.
"This would save lives and help to minimise a public health problem."
He said those sickle cell patients identified as being at the highest risk of death could then be offered treatments such as drugs that can open up their blood vessels or arteries.