Approximately 1.7 million people in England could have undiagnosed killer diseases such as lung cancer, lung disease and heart disease and not know about it. These three health conditions are the top health-related killers in the country at present.

The Public Health England (PHE) has urged people who have a recurring cough or who experience inappropriate breathlessness while doing daily tasks, to see their doctors, especially if these conditions never seemed to bother them before.

On July 14, PHE launched their new campaign "Be Clear on Cancer." The government agency has also warned that the three conditions account for more than 100,000 deaths annually, adding that early detection helps make them treatable.

The health agency estimated that about 1 million people in the country could be suffering from an undiagnosed chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. Moreover, there are approximately 80,000 people in England with undiagnosed cases of lung cancer and 600,000 people with an undetected coronary heart disease.

"Sadly, diagnosis often comes too late, which can have a devastating impact on those living with any of these conditions, as well as those close to them," said Health Minister Jane Ellison.

The agency's "Be Clear on Cancer" campaign is targeting men and women who are 50 years old and above, which is the age group that is the most at risk. According to PHE, breathlessness while doing simple daily tasks such as mowing or vacuuming, or activities that weren't a source of problem years before, could be a sign of lung disease or lung cancer. This could also be a symptom of heart disease.

"The estimated number of people with undiagnosed lung cancer, lung disease or heart disease is deeply concerning," said PHE's National Director for Health and Wellbeing, Professor Kevin Fenton.

Fenton added that the PHE campaign will help people become aware of the diseases' symptoms and encourage them to talk to their doctors and seek medical help. Increased awareness and ability to recognize the symptoms could help in potentially saving lives from the country's three biggest health killers through early detection and successful treatment.

PHE's national "Be Clear on Cancer" campaign will run from July 14 to Oct. 16 this year. The initiative will focus on two symptoms: inappropriate breathlessness and recurring coughs, and three health conditions: lung cancer, lung disease and heart disease.

PHE is working with the National Health Service (NHS) England and the Department of Health for the campaign.