You might wake up feeling perfectly fine, with no signs of illness, yet your arteries could already be partially blocked and your heart quietly under pressure. Blocked arteries often don’t show symptoms until something severe happens—like a heart attack or stroke.

Cardiovascular diseases are responsible for nearly 18 million deaths globally every year, mostly affecting individuals unaware they’re in danger.

Being aware of the following nine symptoms—some of which may seem minor or unrelated—can help you spot trouble early and possibly save your life.

1. Chest discomfort or pain

One of the most common red flags is pressure, tightness, or discomfort in the chest, known as angina.

This is usually caused by atherosclerosis, where plaque made of fat, cholesterol, and calcium builds up inside artery walls. As plaque hardens and narrows the arteries, it restricts blood flow to the heart.

When the heart doesn’t get enough oxygen—especially during physical or emotional stress—it triggers pain that can extend to the neck, shoulders, back, or arms.