Cocaine users are running the risk of developing potentially fatal arterial aneurysms, says research revealed by scientists.

The fresh evidence comes in addition to established links between taking the drug and heart attack or stroke.

A separate study published on Tuesday describes how heroin users who "chase the dragon", or inhale the vapour produced when the drug is heated, can suffer from a condition similar to Creutzfeldt Jacob Disease (CJD).

An aneurysm happens when the wall of an artery balloons out under pressure. If the aneurysm happens in a heart or brain artery, and goes on to burst, it can trigger either a heart attack or stroke.

Researchers at Hennepin County Medical Center in Minneapolis in the United States looked at 112 individuals who admitted using cocaine.

All had a history of chest pains and other cardiovascular health problems.

'Chasing the dragon' can cause brain damage

They found almost one in three had aneurysms in a heart artery - the normal rate in patients with heart symptoms is around five per cent.

"This is an extremely high percentage compared to the overall number of coronary artery aneurysms seen among patients referred to angiography," said Dr Aaron Satran, who led the study.

In addition to the aneurysms, 73% of those studied had high blood pressure, and 71% had high cholesterol levels.

Brain damage from heroin

The heroin study reported a number of patients who had suffered brain damage, all of whom admitted inhaling drug vapours.

"Chasing the dragon", as it is known, is a more common way of taking the drug in modern times because users often believe it is less risky than using a needle.

But doctors, writing in the US journal Neurology, found some users developed spongiform leukoencephalopathy which, like CJD, gives the brain a spongy appearance.

The disease targets specific cells in the brain, blocking nerve impulses and causing the patients to become uncoordinated and have difficulty talking.

Unlike CJD, the onset is swift, and it progresses swiftly.

But while CJD is irreversible and invariably fatal, the brain damage detailed in the study can improve.