Headaches and migraines cost the United States approximately between $13 and $17 billion per year. There is no known cause of headache and migraine, although it is a common feature of many other ailments. Pain, depression, diet, other medications, hormonal changes, stress, illnesses such as cold and flu, and environmental factors (e.g. a lack of oxygen in the air) may cause headaches and migraines. Though there is no known cause, headaches and migraines may be the result of abnormal brain activity resulting in the nerves, blood vessels and chemicals in the brain being affected.
As the causes of headaches/migraine are unknown, treating them – especially long-lasting, persistent ones – is a mystery as well, as they don’t always respond to standard pain relievers. Migraines in particular are difficult to treat, and the usual course of ibuprofen or paracetamol (acetaminophen) may not work. Cannabis may prove to be an effective migraine-killer without the need to use opioids and other potentially addictive and/or dangerous non-steroidal anti-inflammatory drugs (NSAIDs).
The mechanism behind the relief to migraines cannabis provides is unknown, but it could be because of an endocannabinoid deficiency and an abnormal inflammatory response. Cannabis may also dilate blood vessels, allowing more oxygen to circulate around the brain. Currently, a class of drugs known as “triptans” are used as they work by blocking proinflammatory compounds in the brain. However, triptans are expensive, have lots of side-effects such as nausea and vomiting, and insurance companies often limit the amount of triptans that can be dispensed to patients.