Heart disease may be lurking behind these little-known symptoms.

Every year, approximately 805,000 people in America experience a heart attack, as reported by the US Centers for Disease Control and Prevention. It is concerning that many of these individuals might have overlooked important warning signals.

Some of the most telling signs of a cardiac event taking place include pain, tightness or heaviness of the chest; unusual dizziness or fatigue; shortness of breath; and, of course, an irregular heart rate, also known as arrhythmia. Together, these symptoms should be an urgent indication that medical attention is needed.

While most are familiar with the classic signs, Dr. Bhavini Shah of UK-based Lloyd’s Pharmacy spoke to Daily Mail about some of the more subtle symptoms that appear in his cardiac disease patients, including swollen legs, change in eye color and swollen fingertips.

“Reducing fat intake is an effective way to not only lower your risk of coronary heart disease but also help reduce blood pressure and cholesterol levels,” Shah told Daily Mail readers.

Digital clubbing

Digital, or nail clubbing is a sign of poor circulation, causing nails and fingertips to appear round and enlarged. Per the American Heart Association, this occurs due to chronic low blood oxygen levels that prevent oxygenated blood from reaching the body’s extremities, triggering new blood vessels to form and soft tissues to swell — all in an effort to grab at more oxygen. Aside from latent heart disease, digital clubbing can also be an indicator of inflammatory bowel disease, liver cirrhosis and celiac disease.

Fatty halo

Those who notice a blue or gray-ish ring around their eye’s cornea may be seeing a fatty halo, also called arcus senili. Its presence is a hint that levels of blood cholesterol, leading to blocked blood vessels, are too high. In fact, approximately 45% of people over the age of 40, and 70% of those over 60, will develop these lipid deposits around the outside of their iris, Shah told Daily Mail.

Edema

When the heart can’t effectively pump blood throughout the body, fluids may build up in the lower legs, ankles and feet, causing a swelling effect called edema. It’s a clear sign that the heart is weak and cardiac arrest may be imminent. While the legs and feet are usually first to show swelling — due to gravity — patients with more advanced heart disease may also experience swollen hands, puffiness in the face and abdominal bloating.