More than half of all US cannabis patients – 62 per cent, in fact – use the plant to treat chronic pain, according to research published in the journal Health Affairs. Defined as “pain that lasts or recurs for more than three to six months”, chronic pain affects nearly 19 per cent of all Canadians over the age of 18.

Substantial evidence supports cannabis’s effectiveness in treating chronic pain, (check out this study, and this one and this one), so perhaps it shouldn’t be surprising that so many are turning back to this ancient pain treatment.

Here are three reasons that support cannabis’s potential for managing chronic pain:

Cannabis contains natural anti-inflammatories

In the last century, tetrahydrocannabinol, or THC, was most famous for its euphoria-inducing properties, but THC is also an anti-inflammatory with twenty times more potency than aspirin and twice as much of hydrocortisone. Similarly, cannabidiol, more commonly known as CBD, has been shown to reduce arthritic inflammation and inflammatory pain.

But cannabis is more than a collection of cannabinoids. Like other plants, it contains terpenes, essential oils that contribute to its flavour, aroma and effects. Each cultivar or strain of cannabis presents a unique mix of terpenes (which is why some smell like lemons or blueberries, and others like skunk) and therefore unique healing properties. Caryophyllene (also found in black pepper and cinnamon), linalool (lavender), pinene (pine and rosemary) and myrcene (hops and lemongrass) are anti-inflammatory terpenes commonly found in cannabis.

Cannabis may help with the emotional aspects of pain

In a meta-analysis published in JAMA Psychiatry, researchers found that when patients consume cannabis preparations containing THC “it appears that cannabinoids reduce the emotional response to pain, perhaps by inducing euphoria or making the patient susceptible to the suggestion that pain will decrease.”

Similarly, CBD treatment has been shown to reduce anxiety in both humans and animals, a significant finding since anxiety and chronic pain commonly occur together.

Cannabis is a sedative

Pain can prevent sleep, but lack of sleep can create pain, a chicken-and-egg cycle that can be tough to crack. In this context, cannabis’s potential to both ease pain and promote sleep may be helpful.

Cannabis works differently for different people, and not all cannabis products are sedative, but studies have shown that for some patients, even non-sedating CBD may help improve overall sleep (a curious finding since CBD can also promote alertness).

But CBD is not the only, or even the likeliest ingredient in cannabis to improve sleep. The terpenes myrcene and linalool have sedative properties, while several others have anxiolytic (anti-anxiety) effects that may make sleep easier.

THC is a powerful sedative that can reduce sleep latency (the amount of time it takes to fall asleep). However, THC-containing cannabis products may also reduce the REM stage of sleep, potentially resulting in next-day grogginess. These effects may be dose-dependent, and can vary quite a bit between individuals –if you’re interested in exploring cannabis for sleep, pain or any other condition, it’s always advisable to work with a cannabis-trained clinician.