Tension-type headaches are a type of primary headache with no apparent cause. They cause dull pain radiating from the forehead to the neck and shoulders.
Migraine is a severe, recurring headache which may cause visual symptoms (aura). They affect 12% of people, most commonly women, who often have triggers.
Ebola virus is a severe, often fatal infection transmitted by blood or skin contact. It causes fever, fatigue, headache and later gastrointestinal symptoms.
Severe acute respiratory syndrome (SARS) is a contagious lung infection which causes bleeding in the lungs and severe breathing difficulty. It can be fatal.