The stroke risk in your neck gives almost no warning

Two arteries in your neck carry blood to your brain and head. When plaque —
fat, cholesterol, calcium and other substances from the blood — builds up
inside them, they narrow. That is carotid artery disease, and the reason it
matters is simple: the organ downstream is the brain.

The unsettling part is the timeline. **Carotid artery disease often causes no
symptoms at all until the narrowing is severe.** There is no ache that builds
over years and no early warning you can act on. By the time the condition
announces itself, it has usually been developing for a long while.

Two ways it causes a stroke

The distinction is worth knowing, because it explains why a moderate
narrowing is still dangerous.

The second is why "the narrowing isn't that bad yet" is false reassurance. A
fragment from a partially narrowed artery is enough, and where it lands is
decided by the circulation rather than by the size of the original deposit.

The three signs, in the order you are likely to meet them

1. A bruit. A whooshing sound your doctor hears through a stethoscope
   placed over the artery — turbulent flow past a narrowing. This is the only
   sign that costs nothing to look for and arrives before anything has gone
   wrong, which is a good argument for not skipping the part of an
   examination that seems perfunctory.
2. A transient ischaemic attack. A TIA is a stroke that stops. It lasts a
   few minutes and the symptoms usually clear within an hour. The name
   "mini-stroke" is the most dangerous phrase in this subject, because it
   invites people to wait and see whether it happens again. It is the same
   process as a stroke, interrupted — and it is the clearest advance warning
   this disease ever gives.
3. A stroke. No longer a warning.

Imaging tests confirm whether the disease is present. They are not a screening
programme you enrol in unprompted; something usually prompts them.

What can be done

Four treatments, ranging from the everyday to the surgical:

• Healthy lifestyle changes — the same ones that govern plaque anywhere
  in the arterial system.
• Medicines.
• Carotid endarterectomy — surgery that opens the artery and removes the
  plaque physically.
• Angioplasty — a balloon threaded into the artery to open it, and a mesh
  stent left behind to hold it open.

None of these undoes the underlying process; they manage a narrowing that is
already there. Which is another way of saying that the lifestyle item at the
top of the list is doing more work than its position suggests.

Source: National Heart, Lung, and Blood Institute, via MedlinePlus.