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British Lung Foundation
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The effect of cannabis on the lungs - share your experience

Many people don’t realise the effects smoking cannabis can have on your lung health.

A report by the British Lung Foundation (BLF) found that just three cannabis cigarettes can cause the same damage as 20 tobacco cigarettes as the tar from cannabis cigarettes contain 50% more cancer causing carcinogens than tobacco. Recent research suggests that, for some lung diseases, this ratio might be as high as 1 in 20.

Science and statistics aside – has anyone ever smoked cannabis for recreational or medicinal purpose? We’d really like to hear your stories and hear whether you think smoking cannabis has had an effect on your lung health.

Don’t be afraid to get in touch, we want to hear your opinions!

For more information about the effect of cannabis on the lungs visit: lunguk.org/campaigns/media-...

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My Dad has smoked cannibis for a long time .The past couple of years he has used filters with them as well .His emphysema from being diagnosed in 2008 until now has gone from fev1 66% to under 30% easily now in only 4 years .I dont know if the cannibis has made it progress so quickly or if its just the fact that he has continued to smoke once diagnosed.I am so pleased to say my Dad has not touched any sort of cigerette in just over 3 weeks now and has promised he never will again .

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For every report that Cannabis / Marijuana harms the lungs, there is another stating the opposite. I believe the accepted wisdom is that smoking it mixed with tobacco will harm the lungs and leave the smoker addicted to the tobacco - thereby putting them at risk of lung disease.

Smoking Cannabis on its own seems to have no effect on the lung other than a very slight increase in lung function. well.blogs.nytimes.com/2012...

I only ever smoked cigarettes and have very severe COPD. Many friends back in the 60's and 70's smoked both cigarettes and Cannabis regularly, yet not one of them has COPD. Most 'Dope Heads' of that era were white, middle or upper class and well educated. Many a public school dorm had a couple of plants near the window, grown by some young entrepreneur. Many continue/d to smoke both substances well into adulthood and enjoyed well paid respected careers. Why then do we not hear of many politicians, lawyers, judges, scientists, social commentators, journalists, artistes etc getting COPD? Many smoke/d very heavily. Either they see the disease as a shameful secret not to be told, or their higher living standards and private healthcare protected them from the devastation of lung disease.

So no, I never smoked Cannabis, and no I don't think it causes lung disease unless mixed with tobacco. Mix it with tobacco and poverty, and then you have a sure recipe for even higher COPD rates.


Thanks for all the comments – everyone feel free to continue contributing. Don’t be shy!

The article you linked Parvati is really interesting. As you point out, there is conflicting evidence about how COPD and lung function (which the article focuses on) is affected by smoking cannabis. But, of course, if cannabis is smoked with tobacco it will aggravate COPD.

Whilst COPD is a very prevalent lung condition, there are many other lung conditions which cannabis can have a harmful effect on. These include: bronchitis, lung cancer, spontaneous pneumothorax, legionnaires disease, TB and aspergillosis. They’re not quite as common as COPD but there is evidence to suggest smoking cannabis has a harmful effect on these conditions.

Cannabis smoke also contains various chemicals including THC, carbon monoxide, lung irritants and carcinogenic (cancer-causing) substances which are inhaled straight into the lungs.

What does everyone think? Does anyone have one of the lung conditions above and smoked cannabis as well?

Yes okay, but is your intention to actually exclusively (solely/only) criticise and demonise cannabis itself?

Because you do not point out the known beneficial aspects of it, such as how it is widely used for medicinal purposes, one being the appetite stimulating properties it definitely contains, used for that very reason by cancer sufferers who after so many other substances that they must take and chemo, through that have no appetite but where, from cannabis, they find great relief!

I am an ex-user of cannabis and feel it contributed to my COPD but not because of what it is but chemically or other, but instead simply because anything smoked is bound to be bad for the lungs.

You name THC, as a chemical, okay but it is a cannabinoid and that is the very ingredient that smokers go after, seeing as it is what gets one high and which also partly provides thus pain relief and stress relief.

I would hate to think my input and info, plus experience, written here would aid the down-putting of cannabis in line with the usual idiotic demonisation of it.

The right policy in the UK, to my mind, was downgrading it to class c, the wrong policy was ignoring academics when they jointly pointed iout that demonizing cannabis is not right.

Those too who perhaps became paranoid from it, tend as far as I can tell to be people that if not using weed and hash and mking it a problem, would have something else they'd over-do and so it is their own personal attitudes and lifestyles that influence the going nuts on it.

Even the high grade weed cultivated nowadays is not at all as it has been described, all as it is, is GOOD, what wine connoisseur would not want to grow the best grapes from the vest vines?

Anything a person overuses is bad, I know from experience.

If you fail to point out the plusses then I am fst to susp ect that you may possibly know little really about marijuana, as many or most do not too, except for that which they copy from newspapers and the rest of the witchhunt on it.

I must dsay p ersonally i benefited greatly fro m the use of cannbis but not fro m smoking it, the effect on my thinking and behaviour was veery positive, entirely different to the effects, let's say, o f alcohol.

At no time was I ever in any danger at all of progressing from weed and hash to hard drugs, on the contrary, both substances caused me to take pleasure in studying things, and wanting to do things well, so I learned lots about what things actually did to people, I always saw it as having opened my mind more, and that alcohol and hard drugs act differently in that they are means of escape and mind-closing.

Hard drugs are all about kicks.

That's where smoking comes in, because that is a kick activity too, and when tobacco is mixed with weed and or hash, then it is even more so .

I always could drop smoking cannabis any time I liked but I never even attempted to stop smoking tobacco as the nicotine keeping me addicted told me I needed it and could not stop, it told me I liked it. And I did then, but, it wasn't really liking, it was a matter of having no choice in the matter once addicted.

To me, tobacco addiction is as bad and heavy and hard to get off as heroin.

The media aided the promotion of tobacco, there was vast sums of money to be made from it and there still is. I remember if watching a film and seeing someone light up, all the addicts lit up too, myself often included.

In the old films nearly everyone was smoking, so tobacco was accepted and forced onto all others through advertising, I say all others because in planes nobody used to have a choice, there was not a screened-off and separate place/section for non-smokers.

When I read Joe Jackson, the musician, saying that if they banned smoking in public places he'd emigrate, I thought, well, if you ever get cancer, it'd be hard to sympathise with you after your statement on smoking, he being someone in the public eye was rather dumb to say that, if he, at least, had no idea of the influence he could have on people's thinking.

I never did like his music and hated it after that, even though I was a smoker.

I was a smoker but knew it was ridiculous what he was saying.

I see Ron Wood, who supposedly was in danger of getting COPD, continuing to smoke and still nobody is pointing it out, look at Amy Winehouse, she supposedly was suffering with it, hers must have been from smoking hard drugs, I may be wrong but she was very young.

Both my parents smoked, and so did my grandparents, but my brother and sister never did, I recall the reason I started was because it was not allowed and that made it to me as a child naughty and daring, and maybe be engulfed in parental smoke all day egged me on.


Thanks for your comment TJohn - very interesting and thought provoking.

We know that some research suggests cannabis can have medicinal uses such as, the treatment of chronic pain, improving food intake and preventing vomiting due to cancer chemotherapy. However cannabis has also been shown to have a harmful effect on conditions like lung cancer, bronchitis, spontaneous pneumothorax, legionnaires disease, TB and aspergillosis, as mentioned earlier in this discussion.

We are not out to demonise or criticise anyone who smokes cannabis or enter into the debate about legalisation or recategorisation. We want to raise awareness of the health impacts of smoking cannabis as indicated by the latest research. By posting about it on Health Unlocked we wanted to hear of people’s experience with cannabis.

You can read our 2002 report here which highlights the research conducted in this area: lunguk.org/Resources/Britis...

We are looking to publish an update on this report, highlighting the very latest research findings, later this year.

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I think they turn it into a oil ....no smoking involved or tobacco . Nothing like that. Or a spray,there are trials goin on at the moment.for severe Emphesema it seems the only way for the future.


Yes you're right colours, smoking anything is going to irritate the lungs. Taking cannabis for medicinal purposes is taken orally or in supposities and this is where the beneficial effects have been to shown to improve many ailments including COPD.


In this country at the moment it's a spray. No smoking involved .

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Still don't like replying to 'hidden tags' but anyway, I'm sure ingesting any sort of smoke into the lungs would not be helpful, but have read a lot about cannabis being reduced to solid or oil intakes and would welcome the chance to try it.

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Me too, romfty!!

I'm am reading everything I can about this issue and have always agreed that any kind of 'smoke' could not be good for weak lungs. But any substance that is toxic could also be a medicine...

Some of the best medicinal herbs need to be handled carefully as they also have serious side-effects, example; foxglove.

So far, I'm seeing that it's the oil with high THC levels taken as a suppository that seems to work best. I don't care about the 'high' so I have no problem with that.

My only concern is the legality; no one wants to get in trouble for growing/having the stuff. And it seems that some people are even afraid to talk about it. Slowly, here in the states; the laws are changing.

So, in the meantime I'm just doing research...

I'm wondering how you would distinguish the difference in damage between cigarettes and joints, given that joints usually contain tobacco.

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I have COPD and have never smoked a cigarette in my life. I have, however, smoked a lot of pot. The research you mention makes a lot of sense to me. There is no doubt in my mind that my condition is a direct result of "cannabis cigarettes."

I smoked cannabis very heavily from 1968 to about 1974, then tapered off and haven't touched it for thirty years now. Cigarettes were from 1968 to 2003. I'm convinced that the dope was a major factor in my COPD - you inhale hard and you hold it in for a long time. Fun at the time but lots of regrets now! 

I would say smoking anything cannot be good for the lungs, I smoked tobacco from age 14 to 19, never smoked pot, but I now have bronchiectasis. When they talk about cannabis helping COPD, they are not talking about smoking it but ingesting cannabis oil. I'm 70 yrs and was diagnosed at 65 yrs.

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