People with this unusual eye mark are at risk of heart attacks - here's why

Too much cholesterol in the blood is known to be very harmful to the body, especially the heart and blood vessels. 

Cholesterol is called the silent killer because this fatty substance can build up over time without us noticing and cause dangerous blockages leading to a heart attack or stroke.

So, any early warning signs should be acted on immediately, usually by making lifestyle changes like switching to low-fat foods and more exercise. Many people with high cholesterol, known as hypercholesterolemia, don't know they have the condition until they get tested or develop a related health problem.

Yet those with familial hypercholesterolemia, a genetic condition in which there are extremely high levels of cholesterol in the blood, may notice some physical signs. 

Is your cholesterol high? Here are the red flags

One such red flag is an unusual shape that forms in the eye. The US Centers for Disease Control and Prevention (CDC) describes the shape as a whitish-gray color in the shape of a half-moon on the outside of the cornea.

The CDC also states that a doctor may detect physical signs of high cholesterol during an exam, although not everyone who suffers from excess cholesterol has these signs. These physical signs occur when cholesterol accumulates in different parts of the body.

Besides the appearance of the unique half-moon shape, the CDC says other signs are:

• Protrusions or masses around the knees, knuckles or elbows• A swollen or painful Achilles tendon• Yellowish areas around the eyes