An aneurysm is an abnormal swelling or bulge in the wall of a blood vessel, such as an artery. It begins as a weak spot in the blood vessel wall, which balloons out of shape over time by the force of the pumping blood. Usually, aneurysms develop at the point where a blood vessel branches, because the ‘fork’ is structurally more vulnerable. Aneurysms can occur anywhere throughout the circulatory system, but most commonly develop along the aorta (the body’s main artery that runs the length of the trunk from the heart) and in blood vessels of the brain. Aneurysms are potentially fatal if they rupture. Death can occur within minutes.
An aneurysm may have no symptoms (asymptomatic) until it is either very large or it ruptures. Symptoms depend on which blood vessel is affected. Different types of aneurysms include:
A range of causes
- Cerebral aneurysm - this occurs in a blood vessel in the brain. The aneurysm may appear like a tiny blood-filled grape attached to the blood vessel by a stalk. This is known as a saccular or berry aneurysm. These can sometimes form in clusters. Symptoms of a cerebral aneurysm include severe headache with rapid onset, neck pain and stiffness, increasing drowsiness, paralysis, seizures, impaired speech and visual problems. Cerebral aneurysms are more likely in the elderly.
- Thoracic aortic aneurysm - this affects the aorta in the chest. Symptoms include pain in the chest, back and neck, coughing, breathlessness, swallowing difficulties, hoarseness of the voice, swelling of the arms, and a constricted pupil and drooping of the eyelid affecting one eye. In many cases, a thoracic aortic aneurysm is asymptomatic and is discovered by accident during medical examinations for an unrelated condition.
- Abdominal aortic aneurysm - this affects the aorta in the abdomen. Symptoms include pain in the lower back, abdominal swelling, nausea, vomiting, rapid heart rate (tachycardia), sweating and the sensation of a pulse in the abdomen.
Some of the causes of aneurysms include:
High risk of complications
- A weakness in the blood vessel wall that is present from birth (congenital aneurysm).
- High blood pressure (hypertension) over many years resulting in damage and weakening of blood vessels.
- Fatty plaques (atherosclerosis) can result in a weakness of the blood vessel wall.
- Some people have inherited diseases that may result in weaker than normal blood vessel walls.
- Trauma, such as a crush injury to the chest.
- The sexually transmitted disease syphilis, if untreated, can target the aorta and weaken its walls.
- Polycystic kidney disease is associated with an increased risk of cerebral aneurysm.
- Very occasionally, an aneurysm may be caused by an infection targeting and weakening a section of blood vessel.
- The cause sometimes remains unknown.
Depending on the location of the aneurysm, some of the possible complications of an untreated aneurysm include:
- Blood clots within the aneurysm.
- Compression of nearby nerves, if the aneurysm is large enough.
- Blood leaking out of the intact aneurysm into the walls of the artery (dissecting aneurysm).
- Impaired blood circulation beyond the point of the aneurysm.
- Haemorrhage in the layers of tissue surrounding the brain (subarachnoid haemorrhage).
- Water on the brain (hydrocephalus).
- Congestive heart failure.
- Heart attack.
- Kidney failure.
- Sudden death.
An aneurysm is diagnosed using a number of tests including:
- Physical examination
- Ultrasound scans
- Computed tomography (CT) scans
- Examination of cerebrospinal fluid (for a diagnosis of a subarachnoid haemorrhage).
Treatment for an aneurysm depends on its location and severity, but may include:
Surgical repair of aneurysms
- Cerebral aneurysm - surgery to repair the aneurysm (if possible), bed rest and medications (such as painkillers and anti-seizure drugs) to ease associated symptoms. Around half of all people who experience a ruptured cerebral aneurysm die, either within the first day or the next three months. About 50 per cent of the survivors are usually left with lifelong disabilities.
- Thoracic aortic aneurysm - drugs to control high blood pressure and surgery to repair the aneurysm if necessary. Sometimes, the nearby heart valve may also need fixing during the operation. Most people with a ruptured thoracic aortic aneurysm die within minutes.
- Abdominal aortic aneurysm - drugs to control high blood pressure, and surgery to repair the aneurysm if necessary. The mortality rate is more than 50 per cent if the aneurysm ruptures.
If the aortic aneurysm is less than 5cm wide, it is usually left untreated but closely monitored (in case it gets bigger). If larger than 5cm, the aneurysm is surgically repaired. In most cases, the aneurysm is cut out and the hole plugged with an artificial graft. Surgical repair of cerebral aneurysms is not possible if the swelling is located in an inaccessible area of the brain. In some cases, depending on suitability, cerebral aneurysms may be repaired using fine metal coils inserted into the aneurysm via an angiogram. An angiogram is a radiological procedure used, in this case, to close the aneurysm and preserve the normal flow of blood in the brain.
Where to get help
Things to remember
- Your doctor
- Emergency department of your nearest hospital
- Always call an ambulance in an emergency Tel. 000
Blood pressure (high) - hypertension
- An aneurysm is an abnormal swelling or bulge in the wall of a blood vessel, such as an artery.
- Aneurysms can occur anywhere throughout the circulatory system, but most commonly develop along the aorta (the body’s main artery that runs the length of the trunk) and in blood vessels of the brain.
- Aneurysms are potentially fatal if they rupture.
. Circulatory system
. Subdural haematomas
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Article publication date: 30/11/2001
Last reviewed: 30/11/2008
This article, like all health articles on the Disability Online, is sourced from Better Health Channel and has passed through a rigorous and exhaustive approval process. It is also regularly updated. For more information see Better Health Channel quality assurance
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