Aneurysm

A blood vessel can bulge out.

This bulge looks like a little balloon. It happens at a weak spot in the wall. This can happen in the brain or the belly.

As the bulge gets bigger, it might pop. If it pops, it can cause bleeding. Some people are born with these weak spots. Others get them as they grow older. It is important to stay healthy.

An aneurysm is a bulge in a blood vessel.

It happens at a weak spot in the vessel wall. This bulge can look like a tiny balloon. Some people are born with these weak spots. Other people get them as they age.

There are different kinds of aneurysms. A true aneurysm affects all layers of the vessel wall. A false aneurysm, or pseudoaneurysm, is a collection of blood. This blood leaks out but stays near the vessel. This can happen from a wound or surgery.

Shapes can also be different. A saccular aneurysm is round like a berry. It has a small neck. A fusiform aneurysm is shaped like a spindle. It is longer and wider.

These bulges can happen in many places. They can be in the brain or the heart. They often happen in the aorta. The aorta is a very large blood vessel.

An abdominal aortic aneurysm is in the belly.

If an aneurysm grows too large, it might rupture. A rupture is when the vessel pops. This can cause heavy bleeding.

An aneurysm is a bulge in a blood vessel wall. It looks like a tiny bubble or a balloon. This happens because of a weak spot in the vessel. This spot can be there from birth. It can also happen because of a disease later in life.

If the bulge grows too large, it might rupture. A rupture means the vessel pops. This can cause uncontrolled bleeding. This is a very serious event for the body.

There are two main ways these bulges form. A true aneurysm involves all three layers of the vessel wall. These can be caused by things like high cholesterol. A false aneurysm, or pseudoaneurysm, is different. This is a pool of blood that leaks out of a vessel. However, the blood stays near the vessel because of the surrounding tissue.

This can happen from a wound or a surgery. The blood might eventually form a clot to seal the leak.

Scientists also look at the shape of the bulge. Some are called saccular aneurysms. These are round like a berry. They have a small neck that connects to the main artery.

Others are called fusiform aneurysms. These are shaped like a spindle. They are longer and can be wider in many places. The shape does not tell us which disease caused it. The size of the neck helps doctors decide on treatments.

These bulges can appear in many parts of the body. They are often found in the aorta. The aorta is a very large blood vessel.

An abdominal aortic aneurysm is in the belly. Doctors use tools like ultrasound or MRI to find them.

Aneurysms can also be in the brain. These are often called cerebral aneurysms. They can happen in the circle of Willis in the brain. They can also be in the heart, legs, or kidneys.

Many things can increase the risk of an aneurysm. These include things like smoking or high blood pressure. Some people have a family history of them.

Certain conditions, like Marfan syndrome, are also linked to them. A healthy blood vessel is very tough. It can handle the pressure of blood flowing through it. An aneurysm makes the vessel wall thinner and weaker. This makes it much harder for the vessel to stay stable.

An aneurysm is a localized, abnormal bulging of a blood vessel wall. It is often compared to a tiny balloon or a bubble. This bulge occurs because of a weak spot in the vessel structure. Aneurysms can be caused by hereditary conditions or acquired diseases. They can also serve as a nidus, which is a starting point, for a blood clot called thrombosis. As an aneurysm increases in size, the risk of a rupture grows. A rupture can lead to uncontrolled bleeding, which is a very serious medical event.

Doctors classify aneurysms by their type, morphology, or location. A true aneurysm involves all three layers of the arterial wall. These layers are the intima, the media, and the adventitia. True aneurysms can be caused by atherosclerosis, which is a buildup of plaque. They may also be congenital, meaning they are present from birth. In contrast, a false aneurysm, or pseudoaneurysm, is different. This occurs when blood leaks completely out of an artery or vein. The blood is then held in a cavity by the surrounding tissue.

Scientists also describe aneurysms by their macroscopic shape, or their outward appearance. Saccular aneurysms are spherical in shape and are often called "berry" aneurysms. They involve only a portion of the vessel wall and have a "neck" connecting them to the parent artery. This rounded area is known as the dome.

Fusiform aneurysms are spindle-shaped. These vary in both diameter and length. They often affect large sections of the aorta. The diameter of a fusiform aneurysm can extend up to 10 cm. The shape of an aneurysm does not identify the specific disease that caused it.

Location is another way to categorize these bulges. Aneurysms can occur in almost any blood vessel. Cerebral aneurysms occur in the brain, often in the circle of Willis. These can cause severe strokes. Aortic aneurysms affect the body's largest artery. They can be thoracic, located in the chest, or abdominal, located in the belly.

Other locations include the heart, the kidneys, and the legs. For example, a popliteal artery aneurysm occurs in the leg. An abdominal aortic aneurysm is often diagnosed using ultrasonography or MRI.

Size is a critical factor in managing an aneurysm. In the abdominal aorta, an aneurysm is usually defined by a diameter over 3 cm. A normal aorta is approximately 2 cm in diameter. If the diameter is between 2.0 cm and 3.0 cm, it is called ectatic. If it is between 3.0 cm and 5.0 cm, it is moderate. An aneurysm is considered large or severe if the diameter exceeds 5.5 cm. For the common iliac artery, an aneurysm is defined as a diameter of 18 mm or more. These measurements help doctors decide on necessary treatments.

Many risk factors can lead to the formation of an aneurysm. These include diabetes, obesity, and high blood pressure, also known as hypertension. Tobacco use and alcoholism are also significant risks. Some people have connective tissue disorders, such as Marfan syndrome or Ehlers-Danlos syndrome. These conditions affect the strength of the body's tissues. In some cases, infections can cause a mycotic aneurysm. This is an aneurysm that results from a bacterial infection in the arterial wall. Less than 3% of abdominal aortic aneurysms are mycotic.

The mechanical properties of the vessel wall change during an aneurysm. A healthy blood vessel is very tough and can absorb energy before it ruptures. This is due to a high volume of elastin and smooth muscle. In an aneurysmal aorta, the composition changes significantly. There is a much higher volume of collagen and ground substance. However, there is much less elastin and smooth muscle compared to a normal aorta. This makes the vessel wall less stable. The vessel becomes prone to rupture even under normal blood pressure and flow.