What ever could it be????
People aged under 40 are being urged to have their hearts checked because they may potentially be at risk of Sudden Adult Death Syndrome.
The syndrome, known as SADS, has been fatal for all kinds of people regardless of whether they maintain a fit and healthy lifestyle.
SADS is an 'umbrella term to describe unexpected deaths in young people', said The Royal Australian College of General Practitioners, most commonly occurring in people under 40 years of age.
The US-based SADS Foundation has said that over half of the 4,000 annual SADS deaths of children, teens or young adults have one of the top two warning signs present.
Those signs include a family history of a SADS diagnosis or sudden unexplained death of a family member, and fainting or seizure during exercise, or when excited or startled, reported news.com.au.