Posted by NHS Choices on February 18, 2016 · Leave a Comment
Cannabis is the most widely used illegal drug in Britain (*also in the US). Find out about the health risks associated with its use.
There are several health risks associated with cannabis use, including dependency problems, mental health problems and lung damage.
The Effects of Cannabis
The effects of cannabis vary:
- Some people may feel chilled out, relaxed and happy, while others have one puff and feel sick.
- Others get the giggles and may become talkative.
- Hunger pangs are common and are known as ‘getting the munchies’.
- Users may become more aware of their senses or feel that time is slowing down. These feelings are due to its hallucinogenic effects.
- A stronger joint (typically when skunk or sinsemilla is used) may have more powerful effects. Some users may moderate these effects by using less cannabis. Others may find it becomes tempting to binge smoke.
Getting Hooked on Cannabis
As with other drugs, dependence on cannabis is influenced by a number of factors, including how long you’ve been using it, how much you use and whether you are more prone to becoming dependent.
You may find you have difficulty stopping regular use, and you may experience psychological and physical withdrawal symptoms when you do stop. Withdrawal symptoms can include cravings for cannabis, irritability, mood changes, appetite disturbance, weight loss, difficulty sleeping and, in some people, sweating, shaking and diarrhoea.
If you’ve only been using for a short while there should be no problem stopping, but after continued regular use of cannabis, stopping can become more difficult. You’re also at risk of getting addicted to nicotine if you roll your spliffs with tobacco.
Risks Associated with Cannabis
The following risks are associated with cannabis use:
- Even hardcore smokers can become anxious, panicky, suspicious or paranoid.
- Cannabis affects your co-ordination, which is one of the reasons why drug driving, like drink driving, is illegal.
- Some people think cannabis is harmless because it’s a plant, but it isn’t harmless. Cannabis, like tobacco, has lots of chemical ‘nasties’, which, with long-term or heavy use, can cause lung disease and possibly cancer. The risk is greater because cannabis is often mixed with tobacco and smoked without a filter. It can also make asthma worse, and cause wheezing in people without asthma.
- Cannabis itself can affect many different systems in the body, including the heart. It increases the heart rate and can affect blood pressure.
- If you have a history of mental health problems, taking cannabis is not a good idea. It can cause paranoia in the short term, but in those with a pre-existing psychotic illness, such as schizophrenia, it can contribute to relapse.
- If you use cannabis and have a family background of mental illness, such as schizophrenia, you may be at increased risk of developing a psychotic illness.
- It is reported that frequent use of cannabis can cut a man’s sperm count and reduce sperm motility. It can suppress ovulation in women and so may affect fertility.
- If you’re pregnant, smoking cannabis frequently may increase the risk of the baby being born smaller than expected.
- Regular, heavy use of cannabis makes it difficult to learn and concentrate. Some people begin to feel tired all the time and can’t seem to get motivated.
- Some users buy strong herbal cannabis (also known as skunk) to get ‘a bigger high’. Unpleasant reactions can be more powerful when you use strong cannabis, and it is possible that using strong cannabis repeatedly could increase the risk of harmful effects such as dependence or developing mental health problems.
Further Information
For more information on cannabis and the different forms it comes in, see the cannabis section in the Frank website’s A-Z of drugs.
Getting Help if You Use Cannabis
There are several sources of support if you or someone you know has a problem with drugs. Find out more in Drugs: where to get help.
Editor’s Note: *clarification provided for our US readers.


From www.nhs.uk