An aneurysm is when the wall of an artery balloons out like a bubble, weakening (see Circulatory System). Aneurysms most commonly occur in the brain, in the chest, and the abdomen. The latter two happen in the aorta, our largest artery, which exits the heart and heads around down our abdomen. Aneurysms develop gradually over years, nobody knows how & why this happens (in the abdomen, it’s often due to cigarette smoking). There are almost never any symptoms during this time period.
When the aneurysm finally bursts, half the time the bleeding is major, and the patient dies or suffers permanent brain damage. But the other half, there’s a small “warning leak,” and the aneurysm seals itself temporarily. Major rupture will occur within a few weeks, but now there’s time to make a diagnosis & perform life-saving surgery.
The key symptom of an aneurysm leak is very abrupt onset of bad pain, may reach its highest intensity within 60 seconds. In the brain, it causes the “worst headache ever.” The pain is present all the time, doesn’t come and go, but if the blood leak is small the pain may be tolerable. Anyone with such a symptom that doesn’t go away should go to an emergency room.