Experts are urging people to be aware of a red flag for a potentially dangerous health condition that can appear in an unlikely part of the body. While typically symptomless, high cholesterol could cause an unusual sign on the ankles. High cholesterol is a serious issue in the UK, affecting around two in five people.

It occurs when you have too much of a fatty substance known as cholesterol in the blood. If left untreated it can cause narrowing and hardening of the arteries, something which is a significant risk for heart attacks and strokes among other problems. Therefore, the sooner you realise you have high cholesterol and seek help for the condition, the better.

As previously mentioned, it doesn't usually display symptoms. However, this is not always the case. The British Heart Foundation (BHF) warns that people with familial hypercholesterolaemia - a genetic form of high cholesterol - could notice swellings in the ankles and legs. More specifically, it can lead to swelling of the Achilles tendon - the tendon that connects your calf muscles to your heel bone.

Known as tendon xanthomata, these are "swellings made from cholesterol on the knuckles of your hands, your knees or the Achilles tendon at the back of your ankle". Experts at DermNet describe these swellings as "smooth, firm to palpation, and mobile".

They said: "The overlying skin colour is normal. Tendon xanthomas are most commonly associated with familial hypercholesterolaemia, but can also be seen in cerebrotendinous xanthomatosis and sitosterolaemia."

On top of this, swollen ankles can also signal potential heart failure. While swollen ankles do not necessarily mean you have a heart problem, as they have many causes, they are still worth investigating. The BHF explains: "Swollen ankles are common and have lots of causes. For example, they may be caused by tablets you are taking, such as blood pressure medication.

"However, that does not mean you should ignore them, especially if your ankles get very big, as this can be a marker of heart failure. This means that your heart may not be pumping blood around your body as well as it should be, and fluid collects in your lower limbs.

"So, if you're getting swollen ankles, it's worth making an appointment with your GP." The NHS adds that swollen ankles as well as feet and legs are called oedema and could signal a heart problem.

Oedema can appear as:

Swollen or puffy ankles, feet or legs Shiny or stretched skin Changes in skin colour, discomfort, stiffness and dents when you press on the skin.

If you are concerned about your cholesterol levels you should speak to your doctor.