Heart attacks are caused by a lack of blood reaching the heart.
Without enough blood, the heart could become seriously damaged – and it may even be life-threatening.
A heart attack could also be a symptom of coronary heart disease, which is where fatty deposits build up in the arteries, which limits the amount of blood reaching the heart.
One of the unusual warning signs of a heart attack is developing a blue or purple colour on your skin.
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“Warning signs can appear on your skin and nails, which is why your dermatologist may be the first doctor to notice that you have heart disease,” said the American Academy of Dermatology.
“If you know what to look for, you can also find warning signs of heart disease on your skin and nails.
“Blue or purple colour on your skin – What it may be telling you; you have a blockage in a blood vessel.
“If an area of your skin is blue (or purple) when you’re warm, that can be a sign your blood isn’t getting enough oxygen.
“Without treatment, the lack of oxygen can cause the skin and underlying tissue to eventually die.”
Meanwhile, you could also be at risk of a deadly heart attack if you notice red or purple lines underneath your fingernail.
These lines will look almost like a web, and they’re caused by tiny blood vessels bursting.
Small splodges of blood become visible underneath the nail. As the nail grows outwards, these splodges turn into lines of blood, which resemble splinters.
More common heart attack symptoms include severe chest pain, having a radiating pain in your arm, and suddenly feeling very dizzy.
But you can lower your risk of a heart attack by making some small diet or lifestyle changes.
Eating a healthy, balanced diet will lower your chances of fatty deposits in your arteries.
If you think you, or someone you know, may be having a heart attack, it’s crucial that you dial 999 straight away.