Family history might be fascinating, but it can also be life-threatening - particularly if it remains hidden.

This is certainly the case with heart disease, which - although it's not always the case - can run in families. Being aware of this fact could prove life-saving, however, as new research by the British Heart Foundation (BHF) highlights, many families are reluctant to discuss their history of the condition.

Furthermore, according to the findings, released ahead of the the charity's Wear it. Beat it fundraising campaign on February 5, 75% of people know someone in their family with one of the major risk factors for heart disease, including high blood pressure, high cholesterol, being overweight or obese or smoking, but two-fifths (42%) admit they're reluctant to talk about those health issues with them.

HEART OF THE ISSUE

Heart and circulatory disease kills around 155,000 people in the UK each year. Genes and family history aren't always a factor, but they can be, in more ways than one.

Genes can pass on the risk of cardiovascular disease, and also be responsible for the development of other conditions - like high blood pressure or high cholesterol, for instance - which can increase the chances of developing heart problems.

No single gene has been identified as increasing the risk of getting heart disease - it's likely that several genes are responsible, and BHF-funded scientists are finding more all the time (the charity's hoping that Wear it. Beat it will raise £1million to help fund ongoing research).

"Heart disease can strike anyone at any age, without warning. That's why it's vital we do everything we can to reduce our risk and protect our hearts against these devastating conditions," says the BHF's associate medical director, Dr Mike Knapton. "Most people know that the risk of heart disease can be passed on to first-degree relatives, but despite knowing it, two-fifths are reluctant to talk about it, often because of the fear of upsetting someone - people don't like talking about the possibility of death."

FAMILY AFFAIR

So how do you know if an increased risk of developing heart disease runs in your family?

If a first-degree male relative - a father or brother - has suffered a heart attack before the age of 55, or if a first-degree female relative has suffered one before the age of 65, you're generally at greater risk, and if both parents have suffered from heart disease before the age of 55, that risk can rise by 50% compared to the general population.

Certain inherited conditions can also increase the risk of developing heart disease. The most common is familial hypercholesterolaemia (FH), which causes excessively high cholesterol. Tests can also identify people who carry genes responsible for certain heart rhythm disturbances like long QT syndrome, and the inherited form of heart muscle disease cardiomyopathy.

In all, more than 50 inherited cardiac problems have been identified, although genetic testing is not yet available for many.

"Family history of heart disease can be a small to moderate risk, but if you've inherited genes from one of your parents for a condition like FH, for example, there's a 50% chance you're going to have it," explains Dr Knapton. "That means you could have a heart attack and die in your 40s or 50s, but with treatment you can have a normal life expectancy."

KNOWLEDGE IS POWER

While there's nothing you can do about your family history, being aware of it can be extremely positive, as people who know they may be at increased risk can take steps to reduce that risk - and this is what the BHF aims to highlight.

Lifestyle tweaks - like stopping smoking, eating a healthy diet, losing weight and getting enough regular physical activity - are known to make a difference to overall heart disease risk. Plus, if family history of heart problems is openly discussed, people may be more likely to keep a check on their heart by getting cholesterol and blood pressure tests, and attending NHS health checks.

"If you know you're carrying a genetic risk, you're more likely to be eager to attain a healthier diet, weight and physical activity level, and get your blood pressure and cholesterol checked," says Dr Knapton.

"When you've got a moment, bring up the subject of heart disease with your family, and if you do find there's a history, perhaps go to your GP and see what you can do to reduce your risk.

"If you talk about your family history of heart problems, and address your lifestyle as a result, you won't feel so worried about your health - and most of the lifestyle interventions will make you feel better: your mood improves, you sleep better, and you might lose a bit of weight.

"Making small changes, such as walking more, will make you feel better and reduce your risk - not just of heart disease, but other serious health conditions too."

AVOID THE HEARTACHE

Gail Sullivan, 65, from Oxted in Surrey, lost her son Daniel, 43, to a heart attack after he collapsed at work. Daniel had been suffering chest pain the night before, but despite having a history of family members being affected by heart disease, he tragically mistook the pain for indigestion.

"It's been devastating for the family to lose Daniel so young," says Gail. "We've suffered a lot of loss in the family, much of it due to heart disease. Still we didn't really speak about it, and when it came to it, we didn't spot the signs that Daniel was at risk. If we had - if Daniel had - he might still be here.

"That's why it's so important for families to sit down and talk about their risk of heart disease."

:: To sign up for the British Heart Foundation's Wear it. Beat it campaign and wear red on February 5, visit www.bhf.org.uk/red or call 0300 330 0645 for a free fundraising pack.

:: Find out more about your 'heart age' by filling in NHS Choices' Heart Age toolkit, an online questionnaire which assesses your heart age compared to your real age. Visit www.nhs.uk/conditions/nhs-health-check/pages/check-your-heart-age-tool.aspx