The AAA medical abbreviation most often means abdominal aortic aneurysm, a widened, bulging section of the aorta where it runs through the belly. People usually say it as triple A. On a topical prescription, though, the same letters can mean apply to affected area, so the setting tells you which meaning is in play.
In vascular, radiology and primary care records, AAA almost always refers to the aneurysm. It is often found by chance on a scan or through a screening ultrasound, and many are watched over time rather than treated right away. This page explains the size terms on reports, decodes a typical line and covers the pharmacy use.
At a glance
Stands for
Abdominal aortic aneurysm (most common)Pharmacy meaning
Apply to affected area, on creams and ointmentsSaid as
Triple AUsual threshold
Aorta about 3 cm or wider in the bellyUsed in
Vascular surgery, radiology, primary care, emergency careMain tests
Related term
TAA, thoracic aortic aneurysm in the chest
What the AAA medical abbreviation means on a scan
The aorta is the main artery that carries blood from the heart down through the chest and belly. In the abdomen it is normally about 2 centimeters across in adults. When a section widens to about 3 centimeters or more, it is usually called an abdominal aortic aneurysm. Most sit below the kidney arteries, which reports describe as infrarenal.
Many small aneurysms grow slowly and cause no symptoms. The main concern is rupture, a tear that causes severe bleeding inside the belly and is a life threatening emergency. Size and growth rate help the vascular team decide when repair makes sense; in many guidelines that point is around 5.5 centimeters for men, and sometimes smaller for women.
Decoding an AAA ultrasound line
| Words on the report | Plain meaning |
|---|---|
| US abdomen | Ultrasound scan of the belly |
| Infrarenal | Below the arteries to the kidneys |
| AAA 4.2 cm | The widest part of the aneurysm measures 4.2 centimeters |
| Surveillance US in 12 mo | Repeat the ultrasound in a year to check for growth |
Vascular clinic note: "AAA 5.6 cm, grown 0.6 cm in 1 yr, plan EVAR." The aneurysm has reached a size and growth rate where repair is advised, and the plan is endovascular aneurysm repair, where a stent graft is placed through the arteries in the groin.
Screening and risk factors
Abdominal aortic aneurysm is more common in older men, in people who smoke or have smoked, and in those with a family history of aneurysm. In the United States, a one time screening ultrasound is recommended for men aged 65 to 75 who have ever smoked. Other groups may be offered screening based on their own risk. High blood pressure and atherosclerosis are also linked.
Screening and follow up intervals vary by guideline and by hospital, so the schedule in a person's own plan comes from their care team.
AAA as a pharmacy abbreviation
On older handwritten prescriptions and some pharmacy software, AAA can mean apply to affected area. A line such as "hydrocortisone 1% cream, apply AAA BID" asks for a thin layer on the irritated skin twice a day. Pharmacy labels usually print the instruction in full words for the patient. Because the letters also mean an aneurysm, many prescribers and pharmacists prefer to write the plain phrase. Related dosing shorthand is explained on the BID and PRN pages.
Frequently asked questions
What does AAA mean in medical terms?
In most medical records AAA means abdominal aortic aneurysm, a widening of the main artery in the belly. It is usually said as triple A.
What does AAA mean on a prescription?
On a cream or ointment prescription, AAA can mean apply to affected area. Labels handed to patients usually print the full instruction instead.
What size is an AAA?
An abdominal aorta about 3 centimeters or wider is usually called an aneurysm. Larger sizes and faster growth increase the chance that repair will be recommended.
Is AAA the same as an aortic dissection?
No. An aneurysm is a widening of the artery wall, while a dissection is a tear in the inner layer of the wall. They can occur together but are different problems.