People can go years without realizing they have a problem with their heart. Symptoms might be vague and mild, and many heart diseases are 'hidden', which means they are not visible from the outside. "Hidden heart conditions often go undiagnosed for too long, until something goes wrong or it's too late," explains Sindy Jodar, senior cardiac nurse at the British Heart Foundation (BHF). "That's why it is important to never ignore the signs of heart disease and get yourself checked, just to be sure."

While some warning symptoms are obvious, such as acute chest pain and collapse, there are several more indications that something is wrong with your heart or circulatory system. These do not necessarily indicate a cardiac disease, but it is always a good idea to have them checked out.

From tiredness and nausea to fainting, here are some of the less obvious symptoms everyone needs to know about…

1. Feeling unusually tired

A GP says you should not “ignore or downplay unusual levels of tiredness”.

While it’s normal to feel exhausted if you’ve been very busy or lacking sleep, he adds: “Feeling unusually tired, especially if it’s not related to exertion, should be investigated.”

It could be due to something like anaemia, a virus, or even linked to mental health. It could also be related to your heart, so it is important to have it investigated.

2. Subtle discomfort

“Look out for subtle discomfort in different areas of your body, including discomfort or pain in the jaw, neck, back, or stomach, which can be associated with a heart problem,” says Khan. If symptoms are out of the norm for you and aren’t going away, it’s always best to get them checked.

3. Unusual swelling

Perhaps you have noticed your ankles look particularly puffy, or maybe it’s your general tummy area that’s constantly swollen for no apparent reason.

“Unexplained swelling, known as oedema, in the legs, ankles or abdomen, may also be signs of heart failure,” explains doctor.

4. Vomiting and a choking sensation

Sudden vomiting or a choking sensation in your throat is something to be wary of too. “While not every bout of nausea means there could be something serious happening, feeling sick combined with other aches and pains, such as severe chest pain, should ring an alarm bell,” says Jodar.

Yes, it could be a stomach bug, but if you are having sudden spells of vomiting and nausea more regularly and you’re not sure why, don’t delay in get things checked out.

5. Fainting

If you experience sudden fainting, this is a big indicator of something being awry.

“If fainting or any other symptom becomes a problem, consult a healthcare provider and schedule an appointment with a doctor or cardiologist,” says Khan. “Discuss your symptoms, medical history and risk factors with them.

“Your healthcare provider will assess your vital signs and perform a physical examination. Depending on your symptoms and risk factors, you may undergo diagnostic tests like ECGs, echocardiograms, stress tests, blood tests, or more specialised cardiac assessments,” he adds.

6. Shortness of breath

Struggling to catch your breath is not a trivial matter.

“Anyone experiencing shortness of breath during everyday activities or at rest should see their doctor,” says Khan. This is especially the case if it’s accompanied by chest pain – even if it doesn’t seem especially severe. Khan adds: “Mild chest discomfort should always be investigated, but some people mistake this for indigestion or muscular pain.”

7. Unusual sweating

“Feeling hot, clammy and quite sweaty when you haven’t been doing strenuous exercise shouldn’t be ignored,” adds Jodar. “If this is combined with chest pains, it’s important you get yourself looked at.”

8. Heart rate irregularities

Does your pulse sometimes feel jumpy or too fast? Get it checked with your doctor.

Doctor says: “Smartwatches and fitness trackers can provide valuable data about your heart rate and may detect irregularities to some extent. They can help track general trends in heart rate, especially during physical activity or rest.

“However, they are not a substitute for medical-grade monitoring and evaluation… Any concerning symptoms should be evaluated by a healthcare professional for a comprehensive assessment and diagnosis.