There are many types of headaches that can be caused by stress, dehydration, depression, not enough sleep, drinking too much alcohol, a cold, sinusitis, flu, an allergic reaction or a side effect of taking a particular medication.
Some symptoms can be a feel like pressure on both sides of the head, a dull ache or pounding.
Some are mild, others are really painful and can cause pain round the eye.

A migraine is usually an intense headache that occurs at the front or on one side of the head. The pain is usually a severe throbbing sensation. Nausea – feeling queasy and vomiting, increased sensitivity – photophobia (sensitivity to light), phonophobia (sensitivity to sound) and/or osmophobia (sensitivity to smells), visual problems – seeing flashing lights, zigzag patterns or blind spots stiffness or a tingling sensation like pins and needles in neck, shoulders or limbs, problems with co-ordination – feel disoriented or off balance difficulty speaking or loss of consciousness – this only happens in very rare cases.