One of the primary health issues with cannabis is the effect of smoke on the lungs and upper airway. While the risks from long term cannabis smoking are not fully understood, it is assumed by most health professionals that inhaling smoke into the lungs over long periods of time carries increased risks of lung problems. For people with very sensitive lungs and those who are using cannabis as part of a treatment for serious disease, smoking cannabis can be difficult and hard on the body.

Acute effects can include wheezing, coughing, difficulty breathing, and increased mucus production leading to more coughing.

Medium term effects can include decreased lung capacity for exercise, increased respiratory and throat infections, and chronic coughs. Many people (especially asthmatics) experience so much wheezing and chest discomfort that it's not worth the effects.

While some users turn to ingesting cannabis orally, eating cannabis has some downsides which make it unattractive as a replacement for smoking such as difficulty setting dosage, reduced "high", increased sedation, and dramatically increased duration.

One solution to these problems (Zam 1997, 2001) is to avoid using the lungs to extract the cannabinoids from the smoke. Using a technique called "mouth-smoking" or "puffing" commonly used for tobacco cigars, the smoker uses a pipe or joint (not a bong or vaporizer) and pulls smoke into the mouth, holding it there for 30-60 seconds, and then blows it out through the mouth or nose. The lungs are not used, but instead one sucks on the pipe as if drinking through a straw.

Mouth-smoking is not as efficient as lung-smoking and requires approximately 3 times the material for the same level of effect, but for many people efficiency is not an issue. [Erowid Note: As of the mid 2000s, cannabis potency is so high, few sensitive people need to actually inhale to get strong effects from cannabis.]

Many potent varieties of cannabis flowers available around the world in the 1990s and 2000s are so strong that a single lung hit is too much for many people. Using a less

Mouth-smoking has amusing implications for President Clinton's comment: "I didn't inhale".

efficient method can be a practical way to better titrate dosage. With high potency cannabis, a single mouth hit is enough for most people to feel effects. With low potency cannabis, several mouth hits may be required to reach threshold effects.

Pipes and joints reportedly work best for mouth-smoking. While bongs and vaporizers can make lung-smoking less problematic, even a good vaporizer can cause unpleasant lung problems in many people. Most water pipes and vaporizers don't work well for mouthsmoking because it's difficult to pull the required volume with the mouth alone, so many mouthfuls are needed to achieve effects.

Blowing out through the nose is one way to increase efficiency of mouth-smoking, but it can also irritate the sinuses and nasal mucosa. Cannabis users who are extremely sensitive report that blowing out the nose can trigger irritating allergic feelings and discomfort.

Many users are incredulous that cannabis can be smoked without ever pulling into the lungs. Cannabis users with high tolerance report that it can be hard to get their desired effects levels with mouth smoking, but higher potency materials (extract, oil, hash, kief, etc) can be used where necessary to achieve therapeutically useful levels. Some users also report difficulty remembering not to inhale the smoke. As the effects increase, vigilance wanes and lapses in technique are common. With practice, smokers report that they are able to avoid inhaling smoke and can achieve adequate effects without the need to involve their lungs.