A shocking video shows the difference between healthy lungs and those of a smoker who got through one pack of cigarettes a day for 20 years.
Uploaded by North-Carolina based nurse Amanda Eller, the videos show the black, cancer-ridden lungs of a heavy smoker failing to properly inflate.
This is compared to the healthy, red-coloured lungs that are shown inflating and deflating as normal in the videos, which have been shared more than 5,000 times.
Around 15 percent of adults in the US and 17 percent in the UK smoke cigarettes.
Smoking raises a person's risk of developing lung cancer by approximately 23 times and is responsible for 87 percent of all related deaths.