Two main types of headaches have been described: primary and secondary. Primary headaches are the result of small temporary changes to the nerves, blood vessels and muscles in the head, and include migraines and tension headaches. Secondary headaches are triggered by problems elsewhere in the head and are brought on by illnesses like colds and flu. These most commonly occur as congestion and/or sinus headaches. Typically, people fully recover from the flu after a week or two with rest and medication.

What is Exploding Head Syndrome? Exploding head syndrome, originally called ‘snapping of the brain’, is a condition that happens during sleep. It is characterised by noises perceived inside the head during the night. The most common symptom includes hearing a loud explosion-like noise as one drifts off to sleep or upon awakening. The former is a type of hypnogogic hallucination, and the latter is a type of hypnopompic hallucination. Although they are hallucinations, which are imagined, the noises in exploding head syndrome feel very realistic at the time they occur.