Warning: Video contains graphic images
If you're wanting to quit smoking then this video could be the motivation you need.
Footage uploaded to Facebook by an American nurse shows the difference between healthy lungs of a non-smoker and those of someone who's smoked a pack a day for 20 years.
Red healthy lungs can be seen inflating and deflating as normal while the black smokers' lungs struggle to inflate and deflate.
A woman believed to be North Carolina based nurse Amanda Eller says in the video that the cancerous lungs have lost their "elastance" - the ability of lungs to rebound after being stretched during inhalation.
"So they will stretch out but then the recoil of them just snaps right back."
A weaker elastance mean the lungs are stiff, making it harder for the individual to bring in sufficient air.
New Zealand research released in February showed smoking is in decline for youth.
Results from the Action for Smokefree 2025 (ASH) survey showed that out of 25,000 year 10 students, only 2.2 percent smoke daily, compared with 15.2 percent when a similar survey was done in 1999.