What Causes Pain From The Top Of The Head To Down The Neck?

My daughter is 27 and last Thursday suddenly had a pain which travelled from the side of her head over the top and down her neck. Since then her neck has ached...the knobbly bit where it joins the shoulders. She has also complained of aching knees and head, the type of headache that hurts when you first stand up. We went to hospital where blood pressure, pluse and temperature were all normal. But no one actually said what it could be.