Medication overuse headache (MOH)

This can occur when a person overuses painkillers so that they are taking them regularly for at least three months at a high or frequent dose. This results in a 'rebound headache', which can make a person feel like they constantly have a headache. Paracetamol, NSAIDs such as ibuprofen and opioids such as codeine are common culprits. Other drugs used to treat headache and migraine, such as the triptan sumatriptan, can cause medication overuse headache too. 

Other types of headache

Headache can be triggered by something specific, such as hormonal changes, dehydration, eyesight problems, blocked sinuses or cold and flu viruses. There is another, less common, type of headache called a cluster headache. This causes sudden, severe pain on one side of the head, often accompanied by a painful, watering eye and a watering or blocked nostril on the same side.